We report a high-power VECSEL emitting <8W around 615 nm. The gain chip of the laser was grown by plasmaassisted molecular beam epitaxy and it comprised 10 GaInNAs quantum wells. The VECSEL cavity had a V-shaped geometry and a 10-mm-long non-critically phase-matched LBO crystal for second harmonic generation. The cavity incorporated also an etalon and a birefringent filter for controlling the output wavelength. With the aid of the secondharmonic output and the infrared light leaking out from the laser cavity, the single-pass conversion efficiency of the crystal was estimated to have a value of 0.75%.
We report the first monolithic GaAs-based vertical external-cavity surface-emitting laser (VECSEL) operating at 1550 nm. The VECSEL is based on a gain mirror which was grown by plasma-assisted molecular beam epitaxy and comprises 8 GaInNAsSb/GaAs quantum wells and an AlAs/GaAs distributed Bragg reflector. When pumped by an 808 nm diode laser, the laser exhibited an output power of 80 mW for a mount temperature of 16 °C.
Semiconductor optical amplifiers (SOAs) are a well-established solution of optical access networks. They could prove an
enabling technology for DataCom by offering extended range of active optical functionalities. However, in such costand
energy-critical applications, high-integration densities increase the operational temperatures and require powerhungry
external cooling. Taking a step further towards improving the cost and energy effectiveness of active optical
components, we report on the development of a GaInNAs/GaAs (dilute nitride) SOA operating at 1.3μm that exhibits a
gain value of 28 dB and combined with excellent temperature stability owing to the large conduction band offset
between GaInNAs quantum well and GaAs barrier. Moreover, the characterization results reveal almost no gain
variation around the 1320 nm region for a temperature range from 20° to 50° C. The gain recovery time attained values as short as 100 ps, allowing implementation of various signal processing functionalities at 10 Gb/s. The combined
parameters are very attractive for application in photonic integrated circuits requiring uncooled operation and thus
minimizing power consumption. Moreover, as a result of the insensitivity to heating issues, a higher number of active
elements can be integrated on chip-scale circuitry, allowing for higher integration densities and more complex optical
on-chip functions. Such component could prove essential for next generation DataCom networks.
We review recent results concerning the development of dilute nitride based semiconductor disk lasers. We have
demonstrated over 7.4 W of output power at the second harmonic wavelength (around 590 nm) using a β-BBO crystal.
Over 10 W has been demonstrated at ~1.2 μm, and multi-watt output power has been achieved at 589 nm with narrow
linewidth (δν < 20 MHz).
We report a study investigating the power scaling properties of a single gain chip GaInNAs/GaAs semiconductor disk
laser emitting around 1180 nm. The power scaling was done by varying the pump spot diameter between 320 μm and
460 μm. The emission efficiency was assessed for output coupling ratios between 0.1% and 3%. A maximum output
power of 11 W was achieved with a 1.5 % output coupling ratio and a pump spot diameter of 390 μm. The heat from the
active region was extracted by an intracavity diamond heat spreader attached to a water-cooled copper mount.
Dilute nitride semiconductor disk lasers offer a convenient way of producing 570-650 nm radiation required in medicine
and life science. These lasers can produce multi-watt powers with narrow spectra and compact footprints similar to solid
state lasers. The advantage of using semiconductor gain materials is their ability to reach wavelengths that are not
attainable by traditional solid state lasers. Other advantages include a wide tuning range and the possibility for electrical
modulation. Here we demonstrate a narrow band (<30 MHz) yellow (589 nm) disk laser with 2.7 W output power. The
gain mirror of the laser is optically pumped with an 808 nm diode laser. The emission wavelength of the laser can be
tuned over several nanometers by tilting the filter inside the laser cavity.
We demonstrate a dilute nitride (GaInAsN) based gain mirror capable of meeting the wavelength and linewidth
requirements for laser guide stars. The mirror was grown by molecular beam epitaxy on a GaAs(100) substrate. The heat
generated during laser operation was extracted from the active region with a wedged intracavity CVD diamond. An
intracavity birefringent filter was employed for wavelength selection and a YAG etalon for linewidth narrowing. The
laser radiation was intra-cavity frequency doubled to achieve emission at 589 nm. The frequency-doubled semiconductor
disk laser emitted a narrow linewidth beam (~20 MHz) at 589 nm. In a free-running mode, the laser emitted more than
6W of yellow-orange light with a maximum conversion efficiency of 15.5%.
We report a GaInNAs/GaAs-based disk laser producing 7 W output power at 1180 nm wavelength at a temperature of
15 °C. The laser generated more than 5 W of output power when it was forced to operate with a narrow spectrum at 1178
nm. The gain mirror was grown using a molecular beam epitaxy reactor and it comprised 10 GaInNAs QWs and a 25.5-
pair GaAs/AlAs distributed Bragg reflector.
We report a passively mode-locked optically pumped semiconductor disk laser with emission at 1220 nm. Both the gain
and the semiconductor saturable absorber mirrors used to build the laser are based on InGaAsN/GaAs quantum wells
fabricated by molecular beam epitaxy. The growth parameters have been optimized to reduce the detrimental effects of
nitrogen on the emission efficiency. Using a gain mirror comprising ten GaInNAs quantum wells with a relatively low
nitrogen content and a saturable absorber mirror incorporating two GaInNAs quantum wells, we demonstrate generation
of pulses with durations of ~5ps and average powers up to 275mW. We describe the fabrication procedure of the
semiconductor structures and the results of laser characterization.
We report the first use of a Semiconductor Disk Laser (SDL) as a pump source for ~2μm-emitting Tm<sup>3+</sup> (,Ho<sup>3+</sup>)-doped
dielectric lasers. The ~1213nm GaInNAs/GaAs SDL produces >1W of CW output power, a maximum power transfer net
slope efficiency of 18.5%, and a full width half maximum wavelength tuning range of ~24nm. Free-running operation of
a Tm<sup>3+</sup>-doped tellurite glass laser under 1213nm SDL pumping generated up to 60mW output power with 22.4% slope
efficiency. Wavelength tunable output is also obtained from 1845 to 2043nm. Improved performance with output powers
of ~200mW and a slope efficiency of ~35% are achieved by replacing the Tm<sup>3+</sup>-doped glass with a Tm<sup>3+</sup>-doped KYW
active medium. Emission of a Tm3+,Ho3+-codoped tellurite glass laser is also reported with maximum output power of
~12mW and a ~7% slope efficiency. Finally, preliminary investigations of 1213nm-pumping of a Tm<sup>3+</sup>,Ho<sup>3+</sup>-codoped
silica fibre laser lead to 36mW output power with ~19.3% slope efficiency.
We report an essential progress towards the development of efficient GaInNAs-based semiconductor disk lasers
operating at 1220 nm spectral range. The gain mirrors were fabricated by molecular beam epitaxy using a radio
frequency plasma source for incorporating the nitrogen. The typical structure consisted of a 30-pair GaAs/AlAs
distributed Bragg reflector and 10 GaInNAs quantum wells with relatively low content of nitrogen. The growth
parameters and the composition of the structures have been optimized to reduce the detrimental effect of nitrogen on the
emission efficiency. We have achieved a maximum output power of 3.5 W and a differential efficiency of 20%.