High-power distributed feedback laser diode arrays with narrow spectral width over a wide temperature range.

High-power semiconductor lasers with stabilized wavelengths are recognized as exemplary pumping sources for solid-state lasers. This study introduces distributed feedback (DFB) laser diode arrays designed to maintain an extensive temperature locking range. We report experimentally on high-power 808 nm DFB laser diode arrays. The first-order sinusoidal grating was fabricated using nanoimprint lithography, succeeded by inductively coupled plasma (ICP) dry etching and subsequent wet polishing. These 808 nm DFB laser diode arrays have demonstrated a measured output power of 134 W under a pulsed current of 150 A, with the heat sink temperature maintained at 25°C. The slope efficiency was determined to be 1.1 W/A. At a current of 150 A, the laser operated with a narrow spectral width over a wide temperature range, extending from -30 to 90°C, with a temperature drift coefficient of 0.0595 nm/K.

6.1 W single frequency laser output at 1645 nm from a resonantly pumped Er:YAG nonplanar ring oscillator.

A monolithic 1645 nm Er:YAG nonplanar ring oscillator (NPRO) resonantly pumped by a 1532 nm fiber laser is demonstrated. For reducing the energy-transfer upconversion effect, a 0.5% doped Er:YAG nonplanar crystal was used. An up to 6.1 W single frequency laser output at 1645 nm was obtained, with a slope efficiency of 55.2% and an optical efficiency of 48.0%. The linewidth of the Er:YAG NPRO was 14.4 kHz.

Resonantly pumped 1.645 µm high repetition rate Er:YAG laser Q-switched by a graphene as a saturable absorber.

A fiber laser resonantly pumped 1.645 µm passively Q-switched Er:YAG laser is reported. Graphene on a silicon carbide was used as the saturable absorber for the Q-switching. The pulse energy of the 1.645 µm Q-switched Er:YAG laser was 7.05 µJ, with a pulse repetition rate of 35.6 kHz and an average output power of 251 mW.

Resonantly pumped 1.645 µm single longitudinal mode Er:YAG laser with intracavity etalons.

We report on a 1.645 µm single longitudinal mode Er:YAG laser that was resonantly pumped by a 1.532 µm fiber laser, using intracavity etalons to generate single longitudinal mode operation. We obtained 0.749 W single longitudinal mode output power at 1.645 µm from an Er:YAG laser with two intracavity etalons. The M2-factors of the Er:YAG laser were 1.041 and 1.068 in the x and y directions, respectively.

Single-frequency operation of diode-pumped 2 microm Q-switched Tm:YAG laser injection seeded by monolithic nonplanar ring laser.

We present a diode-pumped, 2mum single-frequency Q-switched Tm:YAG laser. The Q-switched laser is injection seeded by a monolithic Tm:YAG nonplanar ring oscillator with the ramp-hold-fire technique. The output energy of the 2mum single-frequency Q-switched pulse is 2.23mJ, with a pulse width of 290ns and a repetition rate of 200Hz. From the heterodyne beating measurement, the frequency difference between the seed laser and the Q-switched laser is determined to be 37.66MHz, with a half-width of the symmetric spectrum of about 2 MHz.

Stable single-frequency output at 2.01 microm from a diode-pumped monolithic double diffusion-bonded Tm:YAG nonplanar ring oscillator at room temperature.

We demonstrate a monolithic double diffusion-bonded monolithic Tm:YAG nonplanar ring laser pumped by a fiber-coupled laser diode. Up to 867 mW single-frequency output at 2.01 microm was obtained from the Tm:YAG system at room temperature, with a slope efficiency and an optical-optical efficiency of 31.6% and 19.2%. The power stability of the single frequency laser was 0.32% within 30 min.