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Ultra narrow-band absorbing surfaces answer a growing demand of precise control of absorption spectra. Starting from a design of guided mode resonator (GMR), we present here a versatile architecture presenting resonances of very high quality factors (up to 10 000) and spectrally adjustable. This design uses multiple slices of dielectrics to focus resonating field in the middle of a metallic waveguide, diminishing its extension in the metal and thus the loss rate of the propagating mode.

It is well established that solid objects can be cooled by harnessing the properties of laser light. A laser-free technique that attains such cooling by tuning thermal radiation could have many practical applications.A method for near-field optical cooling., Author(s): Yannick De Wilde, Riad HaidarAuthor Affiliations:Optical cooling achieved by tuning thermal radiation Until now, optical cooling of solids has been achieved only using laser light[sup.3] . In this approach, [...]

We present an original and compact optical system inspired by the unusual eyes of a Strepsipteran insect called Xenos peckii. It is designed for a field of view of 30[degrees] and is composed of multiple telescopes. An array of prisms of various angles is placed in front of these telescopes in order to set a different field of view for each channel. This type of camera operates in the [ 3 - 5 [micro]m] spectral bandwidth and is entirely integrated in a Dewar in order to maximize its compactness. Experimental images are presented to validate this design. OCIS codes: 110.0110, 110.3000, 110.3010, 110.3080, 110.4190, 130.3990.

A Monte Carlo (MC) model is developed for understanding the avalanche phenomenon in HgCdTe infrared avalanche photodiodes and also the affect of physical and technological parameters. A comparative study is used for explaining the effect of different combinations of scattering processes on the avalanche phenomenon in HgCdTe.

The performances of a compact infrared optical system using advanced pinhole optics for wide field applications are given. This concept is adapted from the classical Tisse design in order to fit with infrared issues. Despite a low light gathering efficiency and a low resolution in comparison with classical lenses, pinhole imagery provides a long depth of field and a wide angular field of view. Moreover, by using a simple lens that compresses the field of view, the angular acceptance of this pinhole camera can be drastically widened to a value around 180[degrees]. This infrared compact system is named pinhole fisheye since it is based on the field lens of a classical fisheye system. OCIS codes: 050.1970, 110.0110, 110.2970, 110.3000, 130.0130, 130.3990.

A model system of resonant semiconductor microcavities analyzes the detection of thermal light by deriving original transfer matrix formalism. The studies give an insight of the gain-bandwidth limitation.

A theoretical investigation of optical parametric oscillations in isotropic semiconductor microcavities is described and discussed.

A sixfold enhancement of infrared (IR) photoluminescence (PL) from thick single crystal Cr:ZnSe under electrical excitation is reported. The baseline PL signal is obtained under a charge-transfer band optical seeding. The electrically enhanced IR signal is localized in the vicinity of the cathode and is shown to be likely related to hole concentration. The various mechanisms involved in this IR light emission will be discussed. [ABSTRACT FROM AUTHOR]

Statistical study of electrical conduction on a large array of devices based on carbon nanotube films shows a weakly dispersive film conductivity, and a specific contact resistance of 1.1 10-6 Ω cm2, which is four orders of magnitude lower than previously reported values. This allows identifying the conductivity of the carbon nanotube films as driven by a fluctuation induced tunneling mechanism. Such results pave the way to the realization of optoelectronic devices, such as highly sensitive light or gas sensor arrays. [ABSTRACT FROM AUTHOR]

In order to reach the optical parametric oscillation in an isotropic semiconductor, it is of prime importance to enhance the nonlinear conversion efficiency per crystal length unity. In this letter, we describe the concept of fractional quasi-phase-matching which is theoretically shown to provide very high conversion yield, close to those of perfectly phase matched scenarios. The conceptual design in the case of second-harmonic generation is presented, along with predicted performances. [ABSTRACT FROM AUTHOR]

Quasi-phase matching is usually obtained by sign reversal of nonlinear susceptibility. This leads to resonant condition on nonlinear material dimensions and/or converted frequencies. We show that this condition is alleviated using total reflection birefringence. Indeed, Fresnel dephasing at reflection can compensate for almost any phase lag between interacting waves. This nonresonant phase-matching scenario allows both large tunability and nonlinear device design tolerance. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

We investigate the mechanisms involved in the funneling of optical energy into subwavelength grooves etched on a metallic surface. The key phenomenon is unveiled thanks to the decomposition of the electromagnetic field into its propagative and evanescent parts. We unambiguously show that the funneling is not due to plasmonic waves flowing toward the grooves, but rather to the magnetoelectric interference of the incident wave with the evanescent field, this field being mainly due to the resonant wave escaping from the groove. [ABSTRACT FROM AUTHOR]

Abstract: A large array of devices based on a carbon nanotubes film was realized. Electrical characterization by the transfer length method enables the determination of the sheet resistance, and contact resistance, which is extremely low. The resistance dispersion is shown to be due to the film non-uniformity, and is low enough to enable the realization of bolometer focal plane arrays. A decrease of the resistance with the temperature is observed and leads to a TCR of . The strong absorption of carbon nanotubes films in the mid infrared transmission band (3–5 μm and of 8–14 μm) enables us to demonstrate the first carbon nanotubes photo response for these wavelengths. [ABSTRACT FROM AUTHOR]

Abstract: In order to fabricate novel infrared sensors, dense films of multi-wall carbon nanotubes have been grown on silicon and alumina substrates, using Plasma enhanced Chemical Vapour Deposition technique. The physical and optical characteristics of the devices were studied using a variety of methods. The carbon nanotube on silicon device showed a peak response at a wavelength of 1.02 μm. The infrared response of the carbon nanotube on alumina device showed that the detection behavior was consistent with a bolometric effect. Measurements have also revealed a wide spectral response from the visible to the long-wave infrared for that sample. [ABSTRACT FROM AUTHOR]

Abstract: We present new theoretical concepts for Fresnel phase matching. A guided wave approach is described, which allows us to intrinsically take into account all the physical processes involved. To cite this article: M. Raybaut et al., C. R. Physique 8 (2007). [Copyright &y& Elsevier]