M. HARHOUZ Ahlam

In order to acquire a miniature refractive index (RI) biosensor with high sensitivity, fast and selective for ultra-low concentrations of molecules, a new Photonic Crystal (PhC) biosensor based on a waveguide coupled to a Fano resonator is proposed for cancer cells detection. An optimized structure of the biosensor can detect cells cancers (Besal, Hela, Jurkat and PC12) in a biological solution deposited on the surface of the resonator. The detection mechanism uses the refractive index as a detection element. The performance of the proposed biosensor is studied by analyzing the variations in the transmission spectrum of different normal and cancer cells. The proposed structure is multimode PhC, with silica as a dielectric material. The finite element method (FEM) have been implemented for studying and investigating the numerical values. The simulation results display that the proposed biosensor attains spectral sensitivities of '513.12 nm RIU−1', '587.28 nm RIU−1 ', '702.35 nm RIU−1 ' and '690.57 nm RIU−1 ' corresponding to Hela cells, PC12 cells, Basal cells and Jurkat cells, respectively. And he qualilty factor Q of the Fano resonance mode can reach 3040.26. Our optimized design ensures easy fabrication with ongoing techniques. This study may open a new way for the development of integrated optical circuits and biosensing.

An ultra-wideband band-stop plasmonic filter (UWB-BSF) in mid-infrared (MIR) range based on metal–insulator–metal (MIM) waveguide coupled with a hexagonal resonator is proposed in this work. Using RSoft CAD commercial software, the designed BSF is numerically and theoretically investigated by the 2D Finite-Difference Time-Domain method. To enhance the BSFs system in mid-infrared, obtaining ultra-wide bandgap width (UWB) with the maximum passband transmission at the left and right of the bandgap and a high value of the rectangular coefficient, we increase the number of hexagonal cavities. Hence, the number of hexagonal resonators controls the range of the filtered wavelength of the BSFs system. In the case of two hexagonal-shaped resonators, the Fano resonance appears on the left and right sides of the bandgap, forming a U-shaped transmission spectrum, which is very helpful for improving the performance of the band-stop filter. Furthermore, by changing the geometric parameters of the hexagonal cavities the filtered wavelength range is shifted toward the near-infrared (NIR) band. The center wavelength of the bandgap of the proposed nano-stop-band filter is adjustable by varying the geometric parameters of the structure. This device operates in the near-infrared (NIR) and mid-infrared (MIR) wavelength ranges. With a larger bandgap width and tunable performance, this proposed nanostructure provides an advantageous application for plasmonic integrated circuits and broadband transmissions.

Photonics crystal sensors, sensitive to light, play a crucial role in discerning minute alterations in a material’s refractive index, finding widespread application, such as in monitoring drinking water quality. Our objective is to fashion a sensor based on a 2D photonics crystal structure and scrutinize optical transformations induced by variations in the bacteria’s refractive index as light traverses the sensor structure. Leveraging Rsoft’s simulation capabilities, we assessed transmission spectra, observing shifts in the bacteria’s refractive index and their consequential impact on the light signal’s frequency and wavelength within the sensor structure. The simulations unequivocally demonstrate that fluctuations in the bacteria’s refractive index significantly affect the light signal’s frequency and wavelength. Consequently, the study underscores the efficacy of the Rsoft-designed optical sensor in discerning bacterial presence in contaminated water, achieving an average sensitivity of 834.344 nm/RIU. In conclusion, the study establishes the success of the optical sensor crafted with Rsoft software in detecting bacteria in polluted water. By monitoring optical alterations during light traversal, variations in the bacteria’s refractive index are translated into discernible shifts in the light signal’s frequency and wavelength, facilitating effective bacteria detection.

This paper describes a two modes refractive index sensor based on photonic crystals (PhCs) for detecting diabetes in human tears samples. PhC-based biosensors are promising platforms to detect the analyte due to their high sensitivity and selectivity, low cost, and can be easily integrated with other electrical components. The proposed PhC biosensor consists of two waveguides coupled with one defective ring-shaped microcavity, the microcavity was created by removing seven lattice holes and shifting the inner ring-shaped hole vertically down by 0.45a, the whole microcavity system is separated from the two waveguides by three holes. The achieved sensitivity for this device comes out to be 659.83 nm RIU−1. The Q-factor, figure of merit (FOM), and limit of detection (LOD) were about 106, 106 RIU−1,and 10−7 RIU respectively. In general, our results revealed that the proposed device has appreciable potential to be used as a powerful tool to detect diabetes using tears. Furthermore, the proposed biosensor can be used as an alternative to painful pinpricks for diabetes testing. A brief comparison between the presented design and related literatures for detecting diabetes using refractive index biosensors is made to ensure effectiveness and the validity of the proposed biosensor. The high performance and simple design of the proposed biosensor make it a suitable candidate for bio-sensing applications.

In this study, we propose an ultra-wideband bandstop filter (UWB-BSF) using a plasmonic MIM waveguide coupled with a stub cavity that is investigated using finite-difference time-domain (FDTD). Air and silver are used as insulators and metals, respectively; silver is characterized by the Drude model. The structure can filter the optical telecommunication wavelengths of 1550 nm and 1310 nm. The transmission peak and the resonance wavelength of the basic structure can be tuned by varying the stub resonator's length and width. In order to improve the filtering function of the bandstop filter at broad bandwidth in the NIR region with maximum transmission peak, the number of stub resonators is increased to two, three, and four stubs with properly studied lengths and a proper horizontal distance between each two stubs. The bandwidth is enhanced from 350 nm, with two stubs, to 620 nm, with three stubs, and 770 nm, with four stubs, respectively. The corresponding filtered wavelength ranges are [1600 nm–1950 nm], [1330 nm–1950 nm] and [1180 nm–1950 nm] respectively. Moreover, with the increase in the number of stubs, the center wavelength achieves a blue shift to lower wavelengths. Further, the paper provides significant applications for plasmonic bandstop filters in highly integrated optical circuits.

In this paper, a two-dimensional photonic crystal refractive index biosensor based on a ring-shaped
cavity has been proposed. It is designed for the diagnosis of malaria-infected red blood cells (RBCs) in the
wavelength range of 1130-1860 nm for TM-polarized light. The proposed biosensor consists of two wave-
guides coupled with one ring-shaped microcavity, which is obtained by removing seven lattice holes, the
microcavity is separated from the two waveguides by three holes. The infiltration of the analyte into the
ring-shaped cavity changes its refractive index, and this variation of the refractive index of infected and
normal uninfected RBCs causes a corresponding wavelength shift at the output terminal. Consequently, a
high sensitivity of more than 700 nm/RIU, an ultra-high-quality factor (Q-factor) of up to 106 giving a sen-
sor figure of merit (FOM) of up to 106 RIU – 1, and a low detection limit of 10 – 7 RIU can be achieved for the
proposed design. The proposed device has also an ultra-compact size of 9.78  8.84 m2 that makes it so at-
tractive for lab-on-a-chip applications. The obtained results have demonstrated that the ring-shaped holes
configuration provides an excellent optical confinement within the cavity region. The proposed design is
simulated using Plane Wave Expansion (PWE) method and Finite-Difference Time-Domain (FDTD) algo-
rithm

Le capteur sujet de la présente invention se rapporte au domaine de mesure électronique de précision. Il entre dans le cadre des capteurs de mesure des pressions hydrostatiques appliquées à une surface donnée. Ce capteur miniature - facilement intégrable lui et son circuit électronique associé sur une même puce- trouve son intérêt dans différents domaine tel que, le contrôle des pression des gazes naturels, et synthétiques, le contrôle de pression de sang, etc.

Le capteur sujet de la présente invention se rapporte au domaine de mesure électronique de précision. Il entre dans le cadre des capteurs de mesure des pressions hydrostatiques appliquées à une surface donnée. Ce capteur miniature - facilement intégrable lui et son circuit électronique associé sur une même puce- trouve son intérêt dans différents domaine tel que, le contrôle des pression des gazes naturels, et synthétiques, le contrôle de pression de sang, etc.

La présente invention a pour objet de la proposition d’un nouveau biocapteur plasmonique miniature, non couteux et hautement sensible, à base d’un guide d’onde MIM couplé à un résonateur de Fano. Ce biocapteur permet de détecter les cellules cancéreuses (Besal, Hela , Jurkat, PC12, MDA-MB-231 et MCF-7) dans une solution biologique déposé sur surface du résonateur. Le mécanisme de détection repose sur la détection sans marquage, qui utilise l’indice de réfraction comme un élément de détection.

This work describes a two modes refractive index sensor based on photonic crystals (PhCs) for detecting diabetes in human tears samples. PhC-based biosensors are promising platforms to detect the analyte due to their high sensitivity and selectivity, low cost, and can be easily integrated with other electrical components. The proposed PhC biosensor consists of two waveguides coupled with one defective ring-shaped microcavity, the microcavity was created by removing seven lattice holes and shifting the inner ring-shaped hole vertically down by 0.45 a, the whole microcavity system is separated from the two waveguides by three holes. The achieved sensitivity for this device comes out to be 659.83 nm RIU− 1. The Q-factor, figure of merit (FOM), and limit of detection (LOD) were about 10 6, 10 6 RIU− 1, and 10− 7 RIU respectively. I

In this work, an ultra-compact plasmonic sensor design based on Multiple Fano Resonances in
MIM waveguide resonator system is proposed. A simple design, which is highly desirable for
plasmonic optical sensing. The plasmonic structure consisting of MIM waveguide coupled with
Defective resonator. The optical sensor is studied and investigated numerically by using the
finite difference time domain method (FDTD). In this proposed structure, multiple Fanoresonant
peaks are obtained in the spectra by employing MIM waveguide coupled with an oval
resonator. Our simulation results show a large range of resonances modes and high
performance of transmission and detection. The intensity and position of the Fano resonance
modes can be adjusted easily and flexibly by alteration the refractive index (RI) of the filling
medium. In comparison to other similar optical sensors, our proposed plasmonic sensor design
has relatively comparable sensitivity, which may have application in plasmonic and
nanophotonic integrated circuits, slow light device, label free detection, nanoscale filter, and
other related plasmonic devices

Plasmonics is a young area of nano-optics research. Owing to its ability to produce nanoscale hot spots, which are close to the size of bioparticles, it has been largely applied in biodetection with enhanced matter/light interactions and heightened sensitivity to refractive index (RI) changes. In this manuscript, we propose a miniature plasmonic RI sensor with high detection performances. Our proposed plasmonic RI sensor based on Fano resonances in a metal-insulator-metal (MIM) waveguide with a nanowall coupled with an oval resonator is presented in this work. The spectral characteristics and the transmission properties of the sensor are extensively analyzed using the finite difference time-domain (FDTD) method. The proposed sensor proves to be highly sensitive for label-free detection with an optimum design. FDTD simulations show that RI sensitivity values can be as high as 3787.9 nm per refractive index unit (RIU).

arious resonance modes, high transmission, and quality factor with simple design are
highly desirable parameters for realizing nano-integrated plasmonic devices. In the context, a plasmonic
structure consisting of two straight waveguides MIM coupled one central defective circular nano-disk
resonator (CNDR) is proposed in this work. The insulator and metal of the proposed plasmonic lter
are air and silver, respectively. The plasmonic lter is designed and investigated numerically by using
the nite difference time domain method (FDTD). Our simulation results indicate that the proposed
plasmonic lter has two transmission peaks with a maximum transmission equal to 80 and 70 percent.
The advantages of the proposed lter are the various resonance modes with high transmission peaks and
high quality factor which reaches 35.27. In view of these features, our proposed structure of plasmonic
lter has the potential to be employed in various devices such as plasmonic demultiplexers and sensors
for optical communication purposes.

In this study, a new ultra compact gas-sensor, based on a 2D photonic crystal
waveguide incorporating with tapered microcavity, is designed to detect small refractive index
changes. The refractive index (RI) sensor is formed by a point-defect resonant cavity in the
sandwiched waveguide on Si slab with triangular lattice. The properties of the sensor are
simulated by using the plane wave expansion (PWE) method and the finite-difference time-
domain (FDTD) algorithm. The transmission spectra of the sensor with different ambient
refractive indices ranging from n = 1.0 to n = 1.01 are calculated. The calculation results show
that a change in ambient refractive index of ∆n=1×10 -4 is apparent. The proposed sensor
achieves a sensitivity (Δλ/Δn) of 523.2 nm/RIU. It was found that the resonance wavelength is
a linear function of the refractive index in under study range. The sensor is appropriate for
detecting homogeneous media.

Owing to Plasmonics’ ability to generate nanoscale hot spots closer in size to bioparticles, it has been broadly applied in biodetection with heightened sensitivity for refractive index (RI) changes and matter / enhanced light interactions [1–5]. In this context, a highly sensitive plasmonic RI sensor based on Fano resonances in metal-insulator-metal (MIM) waveguide coupled with an oval resonator is proposed. The transmission properties are numerically simulated by finite-difference time-domain method. The properties of the proposed structure in the applications of RI sensing are studied in detail, which discloses that the designed plasmonic system can have prospective applications for the integrated optical devices of nanoscale optical switches, sensors and ptical filters.

In 2019, they accounted for 67% (274,000) of all
malaria deaths worldwide, according to the World Health
Organization; the african region was home to 94% of malaria
cases and deaths. In this context, it is vital to detect malaria more
effectively and accurately, we have developed in this paper a two-
dimensional photonic crystal biosensor based on refractive index
changes that can be used to diagnose malaria. The proposed
design is simulated by using the FDTD algorithm. Reasonable
sensitivity, ultra-high quality-factor up to 107 by inserting blood
sample into the cavity and remarkable detection limit can be
achieved for the proposed design.

In this paper, a novel capsule-shaped two-dimensional photonic crystal (2D-PhC) biosensor, which can sense different body fluids and cancer cells for biomedical applications, has been successfully proposed, designed, and evaluated. Simulation and analysis using Plane Wave Expansion (PWE) method and FiniteDifference Time-Domain (FDTD) algorithm have been done to detect blood components and cancer cells, in which samples are taken in liquid form and penetrate a capsule-shaped cavity. It consists of a capsuleshaped cavity coupled to two waveguides, and the sensing region has a capsular geometry and is positioned in the central region of the optical waveguide. The sensing mechanism of the present biosensor is based on changing the refractive index of the analyte. A high sensitivity of 609.25 nm per refractive index unit (nm/RIU), a low detection limit of 3.9 × 10 – 6 RIU and a Q-factor of up to 107 are predicted for a specific sensor-array arrangement in the wavelength range of 1.4367 to 2.0233 µm. These values demonstrate the potentiality of the proposed biosensor. To ensure the validity of the proposed biosensor, a comparison between the results of the present work and related literature for 2D-PhC biosensors has been made.

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Published under licence by IOP Publishing Ltd5th International conference on advanced sciences ICAS5
IOP Conf. Series: Materials Science and Engineering 1046 (2021) 012001
IOP Publishing
doi:10.1088/1757-899X/1046/1/012001
1
Ultracompact gas-sensor based on a 2D photonic crystal
waveguide incorporating with tapered microcavity
A Harhouz 1
, A Hocini 1,*
and H Tayoub 1,2
1
Laboratoire d’Analyse des Signaux et Systèmes, Department of Electronics,
University of M’Sila BP.166, Route Ichebilia, M’Sila, 28000, Algeria.
2
Research Center in Industrial Technologies CRTI, P.O.BOX :64, Cheraga 16014,
Algiers, Algeria
*E-mail: abdesselam.hocini@univ-msila.dz
Abstract. In this study, a new ultra compact gas-sensor, based on a 2D photonic crystal
waveguide incorporating with tapered microcavity, is designed to detect small refractive index
changes. The refractive index (RI) sensor is formed by a point-defect resonant cavity in the
sandwiched waveguide on Si slab with triangular lattice. The properties of the sensor are
simulated by using the plane wave expansion (PWE) method and the finite-difference time-
domain (FDTD) algorithm. The transmission spectra of the sensor with different ambient
refractive indices ranging from n = 1.0 to n = 1.01 are calculated. The calculation results show
that a change in ambient refractive index of ∆n=1×10 -4 is apparent. The proposed sensor
achieves a sensitivity (Δλ/Δn) of 523.2 nm/RIU. It was found that the resonance wavelength is
a linear function of the refractive index in under study range. The sensor is appropriate for
detecting homogeneous media.

Temperature sensor. A highly sensitive temperature sensor based on Fano resonances in metal-insulator-metal (MIM) waveguide with Nano-wall side-coupled to oval resonator is proposed in this work. The Fano resonance is originated from the coherent coupling and interference between the discrete and the continua state. It shows a different profile, which is typically asymmetric and sharp line, in comparison with the Lorentzian resonance profile. The transmission properties are numerically simulated by finite-difference time-domain method. Structural parameters have a key role in the sensor’s sensitivity and transmission spectrum that are studied to systematically analyze the sensing characteristics of such structure. The results of our study indicate that there exist Four-fano resonance peaks in the transmission spectrum. All of which has a linear relationship with the refractive index of the analyte under sensing. Through the optimization of structural parameters, sensitivity of 2.463 nm/∘C is achieved, indicating the designed sensor can pave the way in the nano-integrated plasmonic devices for high-accurate temperature detection.

In this paper, a plasmonic sensor based on a metal-insulator-metal (MIM) waveguide with
a slotted side-coupled racetrack cavity is proposed. The transmission characteristics of the cavity are
analyzed theoretically, and the improvements of performance for the racetrack cavity structure compared
to a single disk cavity are studied. The influence of structural parameters on the transmission spectra
and sensing performances is investigated thoroughly. The achieved sensitivity for the first mode was
S = 959 nm/RIU and S = 2380 nm/RIU for the second one. Its corresponding sensing resolution is
1.04 × 10−5 RIU for mode 1 and 4.20 × 10−6 RIU for mode 2, respectively, and high transmissions are
achieved at the two resonant wavelengths of 898.8 nm and 1857.1 nm. The proposed plasmonic sensor
is a good candidate for designing novel devices and applications, in the field of chemical and biological
sensing, and also in the field of plasmonic filters, switches, etc.

n this study, a new ultra compact gas-sensor, based on a 2D photonic crystal
waveguide incorporating with tapered microcavity, is designed to detect small refractive index
changes. The refractive index (RI) sensor is formed by a point-defect resonant cavity in the
sandwiched waveguide on Si slab with triangular lattice. The properties of the sensor are
simulated by using the plane wave expansion (PWE) method and the finite-difference time-
domain (FDTD) algorithm. The transmission spectra of the sensor with different ambient
refractive indices ranging from n = 1.0 to n = 1.01 are calculated. The calculation results show
that a change in ambient refractive index of ∆n=1×10 -4 is apparent. The proposed sensor
achieves a sensitivity (Δλ/Δn) of 523.2 nm/RIU. I

In this work, ahydrostatic pressure sensor based on a cavity coupled to a photonic crystal waveguide is proposed. A defect is introducedto createa sharp resonance in the structure which makes it useful for detecting pressure changes. The sensing principle is based on the shift of the resonant wavelength with the change refractive index which arises due to the hydrostatic pressure effect. The proposed structure gives a high sensitivity against wide range of pressures and a good quality factor near 3GPa is achieved. Conclusion: The proposed design also shows separated resonant peaks for different indicesand a perfect linear relation between the cutoff wavelength and the pressure which offer a possibility of highly selective pressure detection.

In this paper, a viable design of mid-infrared refractive index sensor based on photonic crystal coupled cavity-two waveguides is proposed. An increasing number of works are dedicated to investigate the behavior of refractive index sensor based on photonic crystal in the mid-infrared range. We define the sensitivity of our sensor by detecting the shift in the resonance wavelength as a function of the refractive index's variations in the region around the cavity. The purpose of this study is to design a highly sensitive mid-infrared photonic crystal sensor. Consequently, an improved sensitivity of 650 nm/RIU (refractive index units) with a detection limit of 0.001 RIU has been obtained. The sensitivity can be improved from 394 nm/RIU to 758 nm/RIU with a detection limit of 0.01 RIU in the wavelength range of 2, 97 µm to 3, 71 µm by increasing the number of the infiltrated holes. The same design has been used as a liquid

Les cristaux photoniques (CPs) sont des structures artificielles réalisées dans le but d’ouvrir une bande interdite suivant les différentes directions, dans cette bande il apparaît une gamme de fréquence pour laquelle la lumière ne peut plus se propager. L’ouverture d’une bande interdite est due à la variation périodique de l’indice diélectrique à l’échelle de la longueur d’onde, cette variation peut être unidimensionnelle, bidimensionnelle ou tridimensionnelle. Ces propriétés rendent les cristaux photoniques intéressants pour de nombreuses applications en optique intégrée. Les applications potentielles des cristaux photoniques sont très vastes : réalisation des cavités résonantes de taille très réduite, des guides d’ondes, des virages, des filtres sélectifs, des fibres optiques et des capteurs. Dans ce contexte, cette thèse vise à l’étude et la conception des capteurs à base de cristaux photoniques bidimensionnels (CP-2D) pour application en optique intégrée. Les biocapteurs CPs à base de guide à cavité couplé CCWG (Coupled Cavities Wave Guide) offrent plusieurs avantages en termes de sensibilité, de facteur de qualité Q élevé et de large gamme de détection. Pour cela, nous avons basé, dans notre étude, sur deux conceptions : biocapteur à indice de réfraction (RI) à base d’une cavité à modulation locale de la largeur d’un défaut linéique, et biocapteur RI à base de guide à cavité couplée. L’objectif est d’améliorer la sensibilité et la limite de détection de ces biocapteurs en fonction des paramètres physiques et géométriques. Nous avons également proposé une nouvelle structure de biocapteur RI à base de guide à cavité couplée. Afin d'acquérir simultanément une sensibilité optimale et une valeur élevée de la transmission de ce biocapteur, notre amélioration a porté sur l’optimisation de la région sensible du biocapteur, seulement les deux lignes de trous d'air localisés de chaque côté de la ligne du défaut ont été modifiés, ainsi que le nombre de trou autour de la cavité. Pour effectuer ces simulations, nous avons utilisé deux logiciels de Rsoft CAD, dont le premier module est appelé BandSOLVE qui est basé sur la méthode des ondes planes (PWE), et le second appelé FullWave, basé sur la méthode des différences finies temporelles (FDTD). Le biocapteur est très sensible à la variation de RI dans les trous d'air, et il peut être optimisé pour réaliser une large plage de mesure et une grande sensibilité. On a calculé une sensibilité de 530 nm/RIU pour une variation d’indice de 0.001 RIU, a été obtenue.

In this work, we design a new pressure sensor based on two-dimensional photonic crystal waveguide coupled
to a point-defect resonant microcavity. The mechanism of sensing is based on the change of the germanium
refractive index as function of the hydrostatic pressure P. The resonant wavelength will shift when pressure
variation induces change in the refractive indexes of the structure. The pressure variation causes the shifting of
defect modes. The properties of the refractive index sensor are simulated using the finite-difference time-domain
algorithm and the plane wave expansion method. These kinds of sensors have many advantages in compactness,
high sensitivity, and various choices of materials.

In this work, we design a new Infiltrated liquid sensor based on a 2D photonic crystal waveguide incorporating a microcavity to sense small refractive index changes. The refractive index (RI) sensor is formed by a point-defect resonant cavity in the sandwiched waveguide with triangular lattice of air holes (index profile of silicon slab nsi=3.42 and air nair=1). The properties of the sensor are simulated using the finite-difference time-domain (FDTD) algorithm and the plane wave expansion (PWE) method (RSoft Photonic Suite). The sensing principle is based on the shift of resonance wavelength λ0, which occurs due to the change in RI of the sensor when the PhC’s air holes are full of homogenous liquid. Several liquids with refractive indices ranging from 1 (the air) to 1.4 were studied and showed that the best sensitivity of 475 nm/RIU and limit of detection of 0.01 RIU can be achieved.

We propose a temperature sensor design based on the two-dimensional (2-D) photonic crystals (PhCs) microcavity coupled to two waveguides. We consider a Si 2-D PhC, and the refractive index (RI) of distilled water in holes has been taken as temperature dependent. The resonant wavelength will shift when temperature variation induces change in the RIs of the distilled water. The temperature variation causes the shifting of defect modes. The transmission characteristics of light in the sensor under different RIs that correspond to the change in temperatures are simulated by using the finite-difference time-domain method. A sensitivity of 84  pm/°C was achieved with the structure proposed. This property can be exploited in the design of a temperature sensor.

In this work, we design a new biosensor concept that uses a microcavity in 2D photonic crystal (PhC) to sense small refractive index (RI) changes. The RI sensor is formed by a point-defect resonant cavity in the sandwiched waveguide with triangular lattice of air holes. The properties of the sensor are simulated using the finite-difference time-domain method. The calculation results show that a change in ambient RI is apparent; the sensitivity of the sensor is achieved. We succeeded to obtain a new sensitivity value of 425 nm/RIU with a detection limit of 0.001 RIU, which proves the ability of the structure to produce biosensor PhC.

In this work, we design a new An ultracompact gas-sensor based on a 2D photonic crystal modified waveguide to sense small refractive index changes. The refractive index (RI) sensor is formed by a point-defect resonant cavity in the sandwiched waveguide with triangular lattice of air holes in SOI substrat. The properties of the sensor are simulated using the finite-difference time-domain (FDTD) algorithm and the plane wave expansion (PWE) method. The transmission spectrums of the sensor with different ambient refractive indices ranging from n = 1.0 to n = 1.01 are calculated. The calculation results show that a change in ambient refractive index of is apparent, the sensitivity of the sensor ( Δλ / Δn ) is achieved with 523.2 nm/RIU. The resonance wavelength is found to be a linear function of the refractive index in the range under study. The sensor is appropriate for detecting homogeneous media.

In this work, we design a new Infiltrated liquid sensor based on a 2D photonic crystal waveguide incorporating a microcavity to sense small refractive index changes. The refractive index (RI) sensor is formed by a point-defect resonant cavity in the sandwiched waveguide with triangular lattice of air holes (index profile of silicon slab nsi=3.42 and air nair=1). The properties of the sensor are simulated using the finite-difference time-domain (FDTD) algorithm and the plane wave expansion (PWE) method (RSoft Photonic Suite). The sensing principle is based on the shift of resonance wavelength λ0, which occurs due to the change in RI of the sensor when the PhC’s air holes are full of homogenous liquid. Several liquids with refractive indices ranging from 1 (the air) to 1.4 were studied and showed that the best sensitivity of 475 nm/RIU and limit of detection of 0.01 RIU can be achieved.

Control of image quality of an earth observation satellite must be permanently carried out during all orbit life. To achieve this, reference images of three types of targets were taken into consideration, by Alsat-1 (First Algerian launched Satellite) between early 2004 and late 2006: The first target is a homogeneous white region (clear snow) of the Antarctica and above the Arctic regions. The second target is a dark region taken by night over the Pacific Ocean in order to emphasize variations of dark noise, The third target is a clear area along the Rail Road Valley (Nevada, United States) in which radiation is measured on the ground and simultaneously to get the absolute calibration of on board instruments. The purpose of this paper is to assess the variation of the camera quality over a three years period of Alsat-1 operations, by analyzing the images reference taken in the period stated above. We also analyzed the channel light sensitivity (green, red and infrared) through a radiometric estimation, pixel by pixel of two images for a typical homogeneous site (scenes with a uniform background radiation) at two distinguished periods of time, while maintaining the same setting. This radiometric evaluation concerns two types of targets only (dark target and bright target). To this aim, we used a variety of assessment methods, all based on mathematical and algorithmic tools. They includes objective assessment such as PSNR (sigle de Peak Signal to Noise Ratio), entropy, AMBE (Absolute Mean Brightness Error-AMBE), etc.., and much more other subjective methods, such as visual analysis,use of statistical indicator, etc...

ALSAT-1 is the first Algerian satellite put into orbit. It was launched November 2002, 28th at 6:07 GMT into a 700 KM sun-synchronous orbit. Alsat-1 payload (SLIM-6) is a multispectral imager, with two banks of 3 channels. Each is equipped with a CCD sensor and an optical convergent associated electronic circuit. The image quality of ALSAT-1 depends on the quality of imager and design. For the control, we must detect and analyze changes in the radiometric quality of the camera caused by aging instruments and satellite. This analysis should be periodic to locate the defects on raw reference images (Dark and Bright Target).

novel optical sensor was designed for the measurement of salinity in
seawater. The principle is to measure the refractive index variation of seawater that
corresponds to the change in salinity. The sensor based on the two-dimensional
photonic crystal (PhC) microcavity coupled to two waveguide. We have used the
FDTD method to simulate the sensor in 2D PhC with triangular lattice of air holes.
The influence of the geometrical parameter and refractive index on transmission are
studied, and an enhancement in sensitivity in 2D PhC is achieved which proves the
ability of the structure to produce salinity sensor using PhC

ALSAT-1 is the first Algerian satellite put into orbit. It was launched November 2002, 28th at 6:07 GMT into a 700 KM sun-synchronous orbit. Alsat-1 payload (SLIM-6) is a multispectral imager, with two banks of 3 channels. Each is equipped with a CCD sensor and an optical convergent associated electronic circuit.
The image quality of ALSAT-1 depends on the quality of imager and design. For the control, we must detect and analyze changes in the radiometric quality of the camera caused by aging instruments and satellite. This analysis should be periodic to locate the defects on raw reference images.
The aim of our study was to analyze the sensitivity of each channel, using reference images (scenes with a uniform background radiation): images taken at night, images over the ocean, or images of snowy areas; were taken by Alsat-1 between early 2004 and late 2006.
In this purpose we used several assessment methods based on mathematical and algorithmic tools. These includes objective assessment and many of subjective method (visual analysis, use of statistical indicator).

La qualité des images du satellite ALSAT-1 dépend de la qualité des instruments de prise de vue « Slim-6 » et de leur conception. Pour la contrôler, un ensemble de mesures radiométriques de l’imageur slim-6 sont effectuées avant le lancement du satellite et pendant le début de son cycle de vie en orbite, en analysant les premières images de référence: images de test faites à travers une sphère d’intégration, images prises de nuit, images au-dessus de l’océan, des images de l’espace lointain, ou des images de zones enneigées. Ensuite, il faut détecter et analyser les variations de la qualité radiométrique de la camera causés par le vieillissement des instruments et du satellite lui même. Cette analyse doit être périodique pour localiser les moindres défauts sur les images brutes. A cet effet, plusieurs images de référence ont été prises par ALSAT-1 entre le début 2004 et la fin 2006. Elles concernent des cibles de région sombre prise de nuit au dessus de l’océan pacifique pour mettre en évidence les variations du bruit d’obscurité.