Eye-safe actively Q-switched microchip laser with an electro-absorbing semiconductor modulator

Area of Science:

• Optics and Photonics
• Semiconductor Lasers
• Quantum Electronics

Background:

• Monolithic microchip lasers offer compact and robust laser solutions.
• Active Q-switching is crucial for generating high-energy laser pulses.
• Semiconductor modulators provide efficient and fast modulation capabilities.

Purpose of the Study:

• To develop and demonstrate the first actively Q-switched monolithic microchip laser utilizing an electro-absorbing semiconductor modulator.
• To characterize the performance of this novel laser system at a 1.55 micrometer wavelength.
• To evaluate the pulse energy, repetition rate, spectral stability, and beam quality.

Main Methods:

• Fabrication of a monolithic microchip laser cavity.
• Integration of an electro-absorbing semiconductor modulator for active Q-switching.
• Characterization of laser output using optical spectrum analyzers, energy meters, and beam profilers.
• Optimization of absorbed pump power and switching voltage.

Main Results:

• Successfully demonstrated the first actively Q-switched monolithic microchip laser at 1.55 micrometers with an electro-absorbing semiconductor modulator.
• Achieved pulse energy of 470 nJ at a repetition rate of 10 kHz with 130 mW absorbed pump power and 2.2 V switching voltage.
• Observed a stable single longitudinal mode output centered at 1.553 micrometers.
• Characterized a near-ideal Gaussian transverse beam profile with an M(2) value of 1.15.

Conclusions:

• The developed laser represents a significant advancement in compact, high-performance laser sources.
• The use of electro-absorbing semiconductor modulators enables efficient active Q-switching in monolithic microchip lasers.
• The laser's stable, high-quality output makes it suitable for various applications requiring 1.55 micrometer radiation.