Tunable high-power narrow-linewidth semiconductor laser based on an external-cavity tapered amplifier

Area of Science:

• Optics and Photonics
• Semiconductor Lasers
• Nonlinear Optics

Background:

• External cavity diode lasers (ECDLs) are crucial for applications requiring tunable, narrow-linewidth sources.
• Improving output power and beam quality in ECDLs remains a key research objective.

Purpose of the Study:

• To demonstrate a high-power, narrow-linewidth tunable laser system based on a tapered semiconductor optical amplifier in an external cavity.
• To investigate the performance enhancements offered by a novel super-large optical-cavity (SLOC) design.

Main Methods:

• Utilized a tapered semiconductor optical amplifier integrated into an external cavity configuration.
• Employed a super-large optical-cavity (SLOC) design to optimize laser performance.
• Characterized the laser system's tunability, output power, linewidth, and beam quality (M2).
• Demonstrated application as a pump source for frequency doubling to generate blue light.

Main Results:

• Achieved a maximum output power of 1.95 W at 803.84 nm.
• Maintained output power above 1.5 W across a 29 nm tuning range (793-812 nm).
• Obtained an emission linewidth below 0.004 nm and M2 < 1.3 over the entire tuning range.
• Generated 24 mW of 405 nm blue light with a conversion efficiency of 0.83%/W.

Conclusions:

• The SLOC design significantly improves the performance of external cavity diode lasers, enabling high-power and narrow-linewidth operation.
• The demonstrated laser system is a versatile and efficient source for various photonic applications, including nonlinear frequency conversion.
• This work presents a promising platform for developing advanced laser sources for scientific and technological applications.