M. Pessa

High power CW red VECSEL with linearly polarized TEM00 output beam

High-power, continuous-wave operation at red wavelengths has been achieved with a vertical external cavity surface emitting laser based on the GaInP/AlGaInP/GaAs material system. Output power of 0.4W was obtained in a linearly polarized, circularly symmetric, diffraction-limited beam. A birefringent filter inserted in the cavity allowed tuning of the laser output spectrum over a 10nm range around 674nm.

Spectral narrowing and locking of a vertical-external-cavity surface-emitting laser using an intracavity volume Bragg grating

We report the use of a volume Bragg grating as an output coupler mirror to improve and stabilize the spectral characteristics of 1058-nm vertical-external-cavity surface-emitting laser which is thermally managed using an intracavity diamond heatspreader. Spectrally narrow and locked emission with up to 645mW of TEM0,0 output power is demonstrated

Low-loss GaInNAs saturable Bragg reflector for mode-locking of a femtosecond Cr/sup 4+/ : forsterite-laser

A GaInNAs saturable Bragg reflector is used to mode-lock a Cr/sup 4+/ : forsterite solid-state laser. This low-loss saturable absorber mediates the generation of tunable femtosecond pulses having durations as short as 62 fs in the 1300-nm spectral region.

Stabilization of passive harmonic mode-locking by amplitude modulation

We demonstrate a fiber laser that is passively mode locked by a semiconductor saturable absorber and stabilized by the amplitude modulation. The synchronization of a dropout-free harmonic mode locking to an external clock was obtained with the pulse characteristics solely determined by the saturable absorber action, and not by the applied amplitude modulation. The results show that significant suppression of undesired harmonics can be obtained with small perturbations provided by the amplitude modulation.

Amplification and laser action in diode-pumped 1.3 /spl mu/m GaInNAs vertical-cavity structures

We report fibre-coupled CW diode pumping of 1.3 /spl mu/m GaInNAs/GaAs vertical-cavity semiconductor optical amplifiers (VCSOAs) and surface emitting lasers (VCSELs). The GaInNAs/GaAs structures are monolithic and are specifically designed for optical pumping, offering advantages in design simplification and added functionality. They allow us to demonstrate up to 1.09 dB of amplification and up to 213 /spl mu/W of 1297.2 nm laser emission. Both the 980 nm pump light and 1.3 /spl mu/m signal are coupled to/from the devices by fibers, giving promising systems-compatible demonstrators of GaInNAs-based amplifier technology.

1.3-/spl mu/m continuously-tunable fiber-coupled GaInNAs VCSEL

We report the single-mode operation of a fiber-coupled, tunable GaInNAs VCSEL operating at 1.3-/spl mu/m. Early results show that the device can be continuously tuned, at room temperature, over 14.5-nm with an output power up to 0.12-mW.

Polarisation and modal characteristics of a 1.3/spl mu/m diamond-microchip GaInNAs vertical external-cavity surface-emitting laser

We report the modal and polarisation properties of a 1300 nm GaInNAs microchip VECSEL and their dependence on pump diameter. The analysis suggests that thermal lensing effects play a significant role in microchip VECSEL mode formation.

Experimental comparison of multiple quantum-well GaInNAs vertical-cavity SOAs

This paper presents the gain characterization and efficiency comparison of two reflection-format 1.3 /spl mu/m GaInNAs vertical-cavity semiconductor optical amplifiers (VCSOAs) having six and fifteen quantum-wells. A maximum gain operation of 19 dB and 17 dB, respectively, is reported.

1.3 /spl mu/m CW GaInNAs VCSEL giving 4.1 mW single transverse mode power

In this paper, we have demonstrated fibre coupled-diode pumping operation of a six QW GaInNAs/GaAs VCSEL showing performance of up to 4.1 mW output coupled into a single-mode fibre at 10/spl deg/C at 1290.7 nm. Laser emission was observed up to a temperature of 95/spl deg/C, and the temperature shift is 0.1 nm/K. The VSCEL structure was grown by solid-source MBE using a nitrogen plasma.

High-power picosecond quasiCW 1.3 /spl mu/m Nd-lasers passively modelocked using novel low-loss GalnNAs SBRs

A spin-off from our work on dilute-N GalnNAs VCSELs has been the development of saturable Bragg reflectors (SBR) based on a single 7 nm-thick Ga/sub 0.65/ln/sub 0.35/N/sub 0.019/As/sub 0.981/ quantum-well grown midway in the final quarter-wave layer of a 21 pair AlAs/GaAs Bragg mirror. The SBR was used as the modelocking element in the high power 1.3 /spl mu/m Nd:YLF laser. The laser was operated quasiCW permitting very high power effective on-time operation in a simple side-pumped laser configuration. The laser was pumped with 360 W peak power at 2% duty cycle (200/spl mu/s at 100 Hz).