Steve Bouhier

Synthesis of a 30-Hz Linewidth Wave Tunable Over 500 GHz

We report on a compact source of 30-Hz linewidth, low-phase noise electrical waves with 500-GHz tunability. These waves are generated by photomixing two distributed feedback laser diodes at 1550 nm, which are frequency stabilized on a fibered cavity. We demonstrate a phase noise suppression down to −90 dBc/Hz at 100-kHz carrier offset frequency of the beat note at 2-, 10-, 18-, 40-, and 92-GHz frequencies. The setup also displays a ~170-kHz frequency drift of the beat note at 10 GHz in the long term over a continuous 7.5-h locking period.

Frequency Stabilization of a Laser Tunable Over 1 THz in an All Fibered System

We report on an all-electrical locking of the optical frequency of a distributed feedback laser diode at 1548 nm tunable over 9 nm on a fibered Fabry-Perot cavity. We demonstrate a 7-MHz servo bandwidth and a frequency noise suppression down to 10 Hz/√Hz at 200-kHz carrier offset frequency in the error signal. From this signal, we estimate the laser linewidth to be 100 Hz at a 10-ms integration time. This stabilized laser will be a component of a compact source of continuous millimeter or submillimeter low phase noise electrical waves.

High spectral purity microwave and terahertz oscillator

We report on the design of an ultra stable microwave/THz oscillator and on the realization and the characterization of its laser source. The tunable oscillator is expected to show below -150 dB rad2/Hz phase instability at an offset frequency of 10 kHz for a 30 GHz carrier frequency, as well as 18 GHz, 100 GHz, 400 GHz and 1 THz carrier frequencies.

Class-A operation of an optically-pumped 1.6 µm-emitting quantum dash-based vertical-external-cavity surface-emitting laser on InP

A continuous-wave 1.6 µm-emitting InAs Quantum Dash-based Optically-Pumped Vertical-External-Cavity Surface-Emitting Laser on InP is demonstrated. The laser emits in the L-band with a stable linear polarization. Up to 163 mW output power has been obtained in multi-transverse mode regime. Single-frequency regime is achieved in the 1609-1622 nm range, with an estimated linewidth of 22 kHz in a 49 mm cavity, and a maximum emitted power of 7.9 mW at 1611 nm. In such conditions, the laser exhibits a Class-A behavior, with a cut-off frequency of 800 kHz and a shot-noise floor of -158 dB/Hz for 2 mA of detected photocurrent.