Jussi Rautiainen

2.6 W optically-pumped semiconductor disk laser operating at 1.57-µm using wafer fusion

We report a wafer fused high power optically pumped semiconductor disk laser incorporating InP-based active medium fused to a GaAs/AlGaAs distributed Bragg reflector. A record value of over 2.6 W of output power in a spectral range around 1.57 microm was demonstrated, revealing the essential advantage of the wafer fusing technique over monolithically-grown all-InP-based structures. The presented approach allows for integration of lattice-mismatched compounds, quantum-well and quantum-dot based media. This would provide convenient means for extending the wavelength range of semiconductor disk lasers.

1.3-µm optically-pumped semiconductor disk laser by wafer fusion

We report a wafer-fused high power optically-pumped semiconductor disk laser operating at 1.3 µm. An InP-based active medium was fused with a GaAs/AlGaAs distributed Bragg reflector, resulting in an integrated monolithic gain mirror. Over 2.7 W of output power, obtained at temperature of 15 °C, represents the best achievement reported to date for this type of lasers. The results reveal an essential advantage of the wafer fusing technique over both monolithically grown AlGaInAs/GaInAsP- and GaInNAs-based structures.

High-power semiconductor disk laser based on InAs∕GaAs submonolayer quantum dots

An optically pumped semiconductor disk laser using submonolayer quantum dots (SML QDs) as gain medium is demonstrated. High-power operation is achieved with stacked InAs∕GaAs SML QDs grown by metal-organic vapor-phase epitaxy. Each SML-QD layer is formed from tenfold alternate depositions of nominally 0.5 ML InAs and 2.3 ML GaAs. Resonant periodic gain from a 13-fold nonuniform stack design of SML QDs allows to produce 1.4W cw at 1034nm. The disk laser demonstrates the promising potential of SML-QD structures combining properties of QD and quantum-well gain media for high-power applications.

Temperature-stable operation of a quantum dot semiconductor disk laser

We demonstrate temperature-independent output characteristics of an optically pumped semiconductor disk laser (SDL) based on quantum dots (QDs) grown in the Stranski-Krastanow regime. The gain structure consists of a stack of 7×3 QD layers, each threefold group being located at an optical antinode position. The SDL emits at 1210nm independent of the pump power density. Threshold and differential efficiency do not dependent on heat sink temperature. Continuous-wave operation close to 300mW output power is achieved using the ground-state transition of the InGaAs QDs.

2.7 W tunable orange-red GaInNAs semiconductor disk laser

We report on a GaInNAs/GaAs semiconductor disk laser frequency-doubled to produce orange-red radiation. The disk laser operates at a fundamental wavelength of 1224 nm and delivers an output power of 2.68 W in the visible region with an optical-to-optical conversion efficiency of 7.4%. The frequency-converted signal could be launched into a singlemode optical fiber with 70-78% coupling efficiency, demonstrating good beam quality for the visible radiation. Using a Fabry-Pérot glass etalon the emission wavelength could be tuned over an 8 nm spectral range.

High power frequency doubled GaInNAs semiconductor disk laser emitting at 615 nm

We report on an optically-pumped intracavity frequency doubled GaInNAs/GaAs -based semiconductor disk laser emitting around 615 nm. The laser operates at fundamental wavelength of 1230 nm and incorporates a BBO crystal for light conversion to the red wavelength. Maximum output power of 172 mW at 615 nm was achieved from a single output. Combined power from two outputs was 320 mW. The wavelength of visible emission could be tuned by 4.5 nm using a thin glass etalon inside the cavity.

High-power quantum-dot-based semiconductor disk laser

Semiconductor disk lasers (SDLs), also referred to as vertical external cavity surface emitting lasers (VECSELs), offer an effective solution for combining high output power with high beam quality, from a power scalable semiconductor laser [1]. The first SDLs based on InAs/GaAs sub monolayer (SML) and InGaAs Stranski-Krastanow (SK) grown quantum dot (QD) gain material were recently demonstrated, with output power of 1.4 W and 0.3 W respectively [2,3]. Here, we report the first multi-Watt cw output from a QD SDL.

Raman fiber laser pumped by a semiconductor disk laser and mode locked by a semiconductor saturable absorber mirror

A 1.6µm mode-locked Raman fiber laser pumped by a 1480nm semiconductor disk laser is demonstrated. Watt-level core pumping of the single-mode fiber Raman lasers with low-noise disk lasers together with semiconductor saturable absorber mirror mode locking represents a highly practical solution for short-pulse operation.

Femtosecond mode-locked holmium fiber laser pumped by semiconductor disk laser

We report on a 2085 nm holmium-doped silica fiber laser passively mode-locked by semiconductor saturable absorber mirror and carbon nanotube absorber. The laser, pumped by a 1.16 μm semiconductor disk laser, produces 890 femtosecond pulses with the average power of 46 mW and the repetition rate of 15.7 MHz.

Quantum Dot Based Semiconductor Disk Lasers for 1–1.3 μm

Optically pumped quantum dot (QD)-based semiconductor disk lasers (SDLs) have been under intense research after their first demonstration and important enhancements of their parameters have been achieved since then. In this paper, we present recent developments in QD-based SDLs emitting in the 1-1.3 μm spectral region. Three different wavelength ranges of 1040, 1180, and 1260 nm were explored. Power scaling up to 6 W was achieved for 1040 and 1180 nm devices and up to 1.6 W for 1260 nm device. New spectral regions were covered by direct emission and frequency doubling was used to demonstrate spectral conversion into visible region with green, orange, and red light. Also, the broad gain bandwidth of QD materials was explored and wavelength tuneability up to 60 nm around 1040 nm, 69 nm around 1180 nm, and 25 nm around 1260 nm was demonstrated. The efficiency of excited and ground state emission in QDs was also compared. All these improvements allow new possibilities in applications of QD SDLs, reveal their potential, and suggest the aims for future research in the field.