Pascal Dubreuil

A GaAlAs-GaAs integrated coherence modulator

This paper presents a novel integrated III-V semiconductor waveguide modulator specially designed to generate optical delays of several hundred micrometers. This is achieved by simultaneous propagation of transverse electric (TE) and transverse magnetic (TM) lowest order modes in an original layered waveguide exhibiting a group birefringence greater than 0.02 at 1.3 /spl mu/m. The device has 40% contrast, a switching voltage of 7 V with a 10-mm long electrode and is suitable for transmission and multiplexing of signals by coherence modulation of light in an optical fiber network powered by a short coherence source such as a superluminescent diode.

Miniaturized Scanning Near-Field Microscope Sensor Based on Optical Feedback Inside a Single-Mode Oxide-Confined Vertical-Cavity Surface-Emitting Laser

We propose and demonstrate an original concept of a near-field sensor using the optical feedback properties of a vertical cavity surface-emitting laser (VCSEL) as the detection principle. This is based on the monitoring perturbation induced in the laser cavity by the backscattered light coming from the specimen. Test images confirm the efficiency of the proposed scanning near-field optical microscopy (SNOM) and a solution for the integration of the proposed architecture is given.

Experimental demonstration of oxide-mode influence in a dual-purpose oxide-confined vertical-cavity surface-emitting laser/resonant detector

We report on design, fabrication, and characterization of a vertical-cavity surface-emitting laser (VCSEL) used as a resonant-cavity-enhanced detector for dual-purpose application. The geometry of this oxide-confined VCSEL takes advantage of the properties of the buried oxide layer to allow both single-mode laser emission and detection on a large surface. Here, we demonstrate the presence and the influence of oxide modes in the optical sensitivity spectrum of the device through spatially localized detection measurements. The wavelength of these modes has been correlated to the dip on the reflectivity spectrum measured at the same area of the device surface.

Highly unbalanced GaAlAs–GaAs integrated Mach–Zehnder interferometer for coherence modulation at 1.3 μm

A novel integrated III–V semiconductor waveguide modulator specially designed to generate an optical delay of 100 μm is presented. This is achieved by simultaneous propagation of the TE fundamental mode in both of the arms of a highly unbalanced Mach–Zehnder interferometer with a 29 μm length difference between both arms. In order to minimize the losses in this complex curved structure, trenches were etched on the outsides of curved sections. The modulator has a contrast of 34%, a switching voltage of 6 V with a 10 mm long electrode and is suitable for the transmission and multiplexing of signals by coherence modulation of light in an optical fiber network powered by a short coherence source, such as a 1.3 μm superluminescent diode.

Study of the photodetection behaviour of oxide-confined vertical-cavity surface-emitting lasers (VCSELs)

Abstract We present a theoretical and experimental study of oxide-confined top-emitting VCSELs used as resonant detectors. Oxide-mode influence on the detection spectrum is discussed.