We demonstrate simultaneous lasing at two well-separated wavelengths in self-assembled InAs quantum-dot lasers, via ground-state (GS) and excited-state (ES) transitions. This effect is reproducible and strongly depends on the cavity length. By a master-equation model, we attribute it to incomplete clamping of the ES population at the GS threshold.

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Grating translation technique as a tool for monitoring phase shifts during holographic recording in azo-polymers J. Appl. Phys. 108, 083540 (2010) Reconstruction of polarized optical images in two-and three-dimensional vector holograms J. Appl. Phys. 106, 083109 (2009) Fixed photorefractive holograms with maximum index-of-refraction modulation in LiNbO3:Fe J. Appl. Phys. 106, 063116 (2009) Formation of holographic fringes on photochromic Ag/TiO2 nanocomposite films Appl. Phys. Lett. 94, 074104 (2009) Oscillating holograms recorded in photorefractive crystals by a frequency detuned feedback loop Photonic band gap materials are holograms with extremely high refractive index contrasts. The refractive index function can be approximated by a small number of plane waves, as a consequence of the photonic crystal periodicity. Photonic crystals can hence be constructed with a simple holographic recording of a very small number of optical plane waves, and appear in this regard as the simplest holograms. Various photonic band gap structures are theoretically analysed and those concepts are illustrated experimentally with the fabrication of a two-dimensional triangular lattice in GaAs. The extension of the method to the three-dimensional diamond structure is discussed.

A unipolar semiconductor laser emitting in the mid-infrared spectral region is demonstrated. The laser scheme relies on a simple three-level system in GaAs/AlGaAs asymmetric coupled quantum wells. Population inversion between excited states is achieved by optical pumping of electrons from the ground state with a CO2 laser. Long-wavelength (≈15.5 μm) laser emission is demonstrated. The laser is operated in the pulsed regime up to a temperature of 110 K and with an output peak power ≈0.4 W at 77 K. Unipolar quantum well semiconductor lasers based on this principle are capable of covering the long wavelength mid-infrared spectral region above 12 μm.

Guided mode resonance filters (GMRFs) are a promising new generation of reflective narrow band filters, that combine structural simplicity with high efficiency. However their intrinsic poor angular tolerance and huge area limit their use in real life applications. Cavity-resonator-integrated guided-mode resonance filters (CRIGFs) are a new class of reflective narrow band filters. They offer in theory narrow-band high-reflectivity with a much smaller footprint than GMRF. Here we demonstrate that for tightly focused incident beams adapted to the CRIGF size, we can obtain simultaneously high spectral selecitivity, high reflectivity, high angular acceptance with large alignment tolerances. We demonstrate experimentally reflectivity above 74%, angular acceptance greater than ±4.2° for a narrow-band (1.4 nm wide at 847 nm) CRIGF.

We demonstrate a mesoscopic self-collimation effect in photonic crystal superlattices consisting of a periodic set of all-positive index 2D photonic crystal and homogeneous layers. We develop an electromagnetic theory showing that diffraction-free beams are observed when the curvature of the optical dispersion relation is properly compensated for. This approach allows us to combine slow-light regime together with self-collimation in photonic crystal superlattices presenting an extremely low filling ratio in air.

Experimental results are presented for an integrated-optical-waveguide-isolator concept. This concept is based on inducing the transverse magneto-optic Kerr effect in a semiconductor InP-based optical amplifier (SOA) by using a transversely magnetized ferromagnetic metal as an electrical contact. As a result, the SOA exhibits nonreciprocal loss/gain for TM polarized light and is easily monolithically integrated with other InP-based active photonic devices. We have designed, fabricated and characterized prototype ferromagnetic metal-clad optical amplifiers for an operation wavelength of 1300nm. In these first generation devices we obtained isolation strengths of up to 2.0dB∕mm.

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