Antoine Monmayrant

Mesoscopic self-collimation and slow light in all-positive index layered photonic crystals.

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.

Precise Frequency Spacing in Photonic Crystal DFB Laser Arrays

We have developed integrated distributed-feedback laser arrays using photonic crystal waveguide on a membrane. They exhibit stable single-mode emission. Using both different lattice constants and a method called affine deformation of the crystal, we obtained extended control over the lasing wavelength. Laser arrays with laser-to-laser wavelength shifts as small as 0.3 nm are achieved.

Optimisation of NOPA output pulse shaping using an AOPDF with dispersion self-correction

Shaping of ultrashort visible pulses (500-680 nm) has been performed using an acousto-optic programmable dispersive filter. 50% diffraction efficiency, pulse duration shorter than 30 fs and pulse shaping on 4 ps have been obtained.

Microbubbles for optofluidics: controlled defects in bubble crystals

AbstractnWe use liquid–gas microfluidics as a low-cost, tunable microstructuring tool, for which applications can be envisioned in optics. In order to obtain relevant geometries for photonics, beyond simple self-assembled crystals, we propose an original approach that excludes bubbles from chosen zones thanks to tiny pillars. To assess the strength of the exclusion mechanism, we predict the behaviour of a single flattened bubble in front of a thin cylindrical pillar located in a rectangular microchannel. The model compares the hydrodynamic force Ffluid that pushes the bubble and the force Fs, due to surface tension, resulting from the surface augmentation when the bubble rises over the pillar. The resulting predictions have been confirmed by experimental results which showed that the bubble passes over the pillar if Fsxa0<xa0Ffluid and goes around it in other cases. Consistently with this model, dynamic bubble crystals with controlled lacuna defects of one, two, or a line of bubbles have been successfully produced. Defects can be switched on or off by changing the flow. Using a photosensitive polymer as a carrier liquid, static bubble crystals have also been produced.n

All Photonic Crystal DFB Lasers Robust Toward Optical Feedback

We introduce and demonstrate experimentally that 2-D photonic crystals (PhC) allow the integration of single-mode distributed-feedback (DFB) lasers with both a precise control of the emission wavelength and a high robustness toward optical feedback. This work is based on double deformation , a novel approach, offering theoretical Q-factors above 6×105 for high volume guided mode. Experimentally, DFB lasers on a GaAs membrane, lasing around 1 μm, show stable single-mode emission with unaltered performances under high optical feedback of around 15% in energy.

Tunable wavelength pulse shaping of visible NOPA outputs with an Acousto-Optic Programmable Dispersive Filter

An Acousto-Optic Programmable Dispersive Filter (AOPDF) is used to pulse shape a NOPA. We analyse limitations due to spectral dispersion, Kerr effect and acoustic attenuation. Better than 30 fs pulse duration is experimentally demonstrated.

Design of angularly tolerant zero-contrast grating filters for pixelated filtering in the mid-IR range

Zero-contrast gratings (ZCG) can be used to implement narrow bandpass transmission filters. However, they suffer from poor angular tolerance, which hinders their use in pixelated applications. Combining ZCG with double-corrugation grating, we increase the resonance width and angular tolerance of the filter by more than 1 order of magnitude. Filters tunable around 4.6 μm with more than 90% transmission and compatibility with 140 μm pixel size are demonstrated.

Random laser on planar GaAs waveguides

We demonstrate random lasing emission in an active planar slab of AlGaAs/GaAs randomly perforated with subwavelength circular holes. Spectrally-resolved imaging of both the diffusion in the passive regime together with the lasing emission allows identifying exteneded lasing modes in the weakly diffusive regime.

All photonic crystal DFBs for laser arrays

Planar 2D photonic crystals are of tremendous interest for integrated optics applications. In the last years, several possible laser cavities have been proposed in that prospect. In this paper, we review our work on 2D photonic crystal second order DFB lasers. We will show that an affine deformation of the photonic crystal allows the fabrication of closely spaced arrays of high Q DFB lasers. Combining waveguide and photonic crystal affine deformations, we demonstrate arrays of optically pumped single mode DFB lasers with controlled wavelength spacing. Potential extension of this scheme will be discussed, altogether with potential for electrical pumping implementation.

Photonic crystal single-mode DFB laser array with precise frequency spacing

We have developed integrated DFB laser arrays using photonic crystal waveguide on membrane. They exhibit stable and controlled single-mode emissions with wavelength spacings as small as 0.3 nm.