Power scalable semiconductor disk lasers for frequency conversion and mode-locking

Journal Article · Wed Dec 31 00:00:00 EST 2008 · Quantum Electronics (Woodbury, N.Y.)

DOI:https://doi.org/10.1070/QE2008V038N12ABEH013965· OSTI ID:21466509

Okhotnikov, O G ^[1]

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1. Optoelectronics Research Center, Tampere University of Technology (Finland)

The semiconductor disk laser, a relatively novel type of light oscillators, is now under intensive development. These lasers produce an excellent beam quality in conjunction with a scalable output power. This paper presents recent achievements in power scalability, mode-locking and frequency conversion with optically-pumped semiconductor disk lasers. A novel concept for power scaling described here allows the thermal load of the gain material to be reduced, increasing the threshold of rollover and extending the capability for boosting the output power without degradation in the beam quality. The proposed technique is based on the multiple gain scheme. The total power of over 8 W was achieved in dual-gain configuration, while one-gain lasers could produce separately up to 4 W, limited by the thermal rollover of the output characteristics. The results show that the reduced thermal load to a gain element in a dual-gain cavity allows extending the range of usable pump powers boosting the laser output. Orange-red radiation required for a number of challenging applications can be produced through frequency-doubling using a GaInNAs/GaAs laser. Using such a disk laser operating at a fundamental wavelength of 1224 nm, we demonstrate 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 single-mode optical fibre with 70%-78% coupling efficiency, demonstrating good beam quality for the visible radiation. Using a Fabry-Perot glass etalon, the emission wavelength could be tuned over an 8-nm spectral range. We report on optically-pumped disk lasers passively mode-locked with a semiconductor saturable-absorber mirror. The potential of harmonic mode-locking in producing pulse trains at multigigahertz repetition rates has been explored. The mode-locked disk laser is investigated for different designs of the gain medium that allow bistable mode-locking to be controlled. An explanation for hysteresis of mode-locking is given based on a laser model including saturable absorption and unsaturated gain in a semiconductor oscillator operating in pulsed regime. (invited paper)

• OSTI ID: 21466509
• Journal Information: Quantum Electronics (Woodbury, N.Y.), Vol. 38, Issue 12; Other Information: DOI: 10.1070/QE2008v038n12ABEH013965; ISSN 1063-7818
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABSORPTION
DESIGN
EFFICIENCY
EMISSION
FABRY-PEROT INTERFEROMETER
GALLIUM ARSENIDES
GLASS
HYSTERESIS
INDIUM ARSENIDES
LASER CAVITIES
MIRRORS
MODE LOCKING
OPTICAL FIBERS
OPTICAL MODES
OPTICAL PROPERTIES
OSCILLATORS
PHOTON BEAMS
PULSES
PUMPING
SEMICONDUCTOR LASERS
SIGNALS
VISIBLE RADIATION
WAVELENGTHS
ARSENIC COMPOUNDS
ARSENIDES
BEAMS
ELECTROMAGNETIC RADIATION
ELECTRONIC EQUIPMENT
EQUIPMENT
FIBERS
GALLIUM COMPOUNDS
INDIUM COMPOUNDS
INTERFEROMETERS
LASERS
MEASURING INSTRUMENTS
OSCILLATION MODES
PHYSICAL PROPERTIES
PNICTIDES
RADIATIONS
SEMICONDUCTOR DEVICES
SOLID STATE LASERS
SORPTION