Single photon MIR upconversion detector at room temperature with a PPLN ridge waveguide.

In this paper we describe an upconversion detector in the mid infrared (around 3.5 µm). We take advantage of the PPLN ridge waveguide technology to achieve single photon detection at room temperature on a single spatial mode. With a pump power of 192 mW we obtain a detection efficiency of 0.4% for 22k dark count per second, which corresponds to a noise equivalent power of 3.0 fW · Hz-1/2 and an internal conversion efficiency of 85 %/W of pump.

Effect of spectral sampling on the temporal coherence analysis of a broadband source in a SFG interferometer.

In the frame of sum frequency generation of a broadband infrared source, we aim to enlarge the converted bandwidth by using a pump frequency comb while keeping a high conversion efficiency. The nonlinear effects are simultaneously induced in the same nonlinear medium. In this paper, we investigate the spectral filtering effect on the temporal coherence behavior with a Mach-Zehnder interferometer using two pump lines. We show that joined effects of quasi-phase matching and spectral sampling lead to an original coherence behavior.

Demonstration of a frequency spectral compression effect through an up-conversion interferometer.

This paper reports on the experimental implementation of an interferometer featuring sum frequency generation (SFG) processes powered by a pump spectral doublet. The aim of this configuration is to allow the use of the SFG process over an enlarged spectral domain. By analyzing the converted signal, we experimentally demonstrate a frequency spectral compression effect from the infrared input signal to the visible one converted through the SFG process. Recently, such a compression effect has been numerically demonstrated by Wabnitz et al. We also verify experimentally that we fully retrieve the temporal coherence properties of the infrared input signal in the visible field. The experimental setup permits to demonstrate an experimental frequency spectral compression factor greater than 4. This study takes place in the general field of coherence analysis through second order non-linear processes.

Phase closure retrieval in an infrared-to-visible upconversion interferometer for high resolution astronomical imaging.

This paper demonstrates the use of a nonlinear upconversion process to observe an infrared source through a telescope array detecting the interferometric signal in the visible domain. We experimentally demonstrate the possibility to retrieve information on the phase of the object spectrum of an infrared source by using a three-arm upconversion interferometer. We focus our study on the acquisition of phase information of the complex visibility by means of the phase closure technique. In our experimental demonstration, a laboratory binary star with an adjustable photometric ratio is used as a test source. A real time comparison between a standard three-arm interferometer and our new concept using upconversion by sum-frequency generation demonstrates the preservation of phase information which is essential for image reconstruction.

Unprecedented Raman cascading and four-wave mixing from second-harmonic generation in optical fiber.

We experimentally demonstrate strong second-harmonic-generation from a self-induced all-optical poling in germanium-doped fiber with a subnanosecond laser pump at 1064 nm. The large second-harmonic conversion efficiency allows nonlinear spectral broadening at visible wavelengths so that up to nine distinct Raman sidebands have been obtained. In this work we emphasize how the Raman scattering, induced from the pump in the IR region, can drastically affect the optical poling effect, limiting in turn second-harmonic generation.

Novel active Q-switched fiber laser based on electrostatically actuated micro-mirror system.

It has come to the attention of the Optical Society of America that this article should not have been submitted owing to its substantial replication, without appropriate attribution, of significant elements found in the following previously published material: A. Crunteanu, D. Bouyge, D. Sabourdy, P. Blondy, V. Couderc, L. Grossard, P. H. Ploger and A. Barthelemy, "Deformable micro-electromechanical mirror integration in a fibre laser Q-switched system," J. Opt. A: Pure Appl. Opt. 8 S347-S351 (2006).

Ultra wide band supercontinuum generation in air-silica holey fibers by SHG-induced modulation instabilities.

Second harmonic generation in an air-silica microstructured optical fiber pumped by subnanosecond pulses is used in order to initiate modulation instability processes in normal and anomalous dispersion regimes. This allows us to generate an ultra wide and flat supercontinuum (350-1750 nm), covering the entire transparency window of silica and exhibiting a singlemode transverse profile in visible range.

Raman cascade suppression by using wide band parametric conversion in large normal dispersion regime.

We present experimental results on the suppression of a complete Raman cascade in a holey fiber by using gain competition with parametric processes. The modulation instabilities which strongly affect the stimulated Raman scattering (SRS) gain are induced by two pump wavelengths (532 nm, 1064 nm) placed far and quasi symmetrically on each side of the zero dispersion wavelength (ZDW) of the fiber (790 nm). The competition between these two nonlinear effects takes place in large normal dispersion regime. We experimentally determinate the quantity of energy needed at each pump wavelength to obtain total suppression of the SRS and we evaluate the sensitivity of this effect with respect to the ZDW position.