Two-stage injection locking of high-power semiconductor arrays

Area of Science:

• Optics and Photonics
• Semiconductor Lasers
• Quantum Well Devices

Background:

• Single-stage diode-array injection-locking techniques have limitations in power extraction and gain.
• Achieving high power, single-frequency, and narrow linewidth output from diode arrays is crucial for various applications.

Purpose of the Study:

• To demonstrate a new multistage diode-array injection-locking technique.
• To achieve higher power extraction and overall gain compared to single-stage designs.
• To characterize the small-signal and saturated gain performance of the developed system.

Main Methods:

• Utilized a multistage injection-locking approach with two antireflection-coated 40-stripe multiple-quantum-well diode arrays.
• Characterized amplifier performance under small-signal and saturated conditions.
• Measured output power, frequency stability, linewidth, and far-field beam quality.

Main Results:

• Achieved over 500 mW of output power.
• Maintained single-frequency operation with a narrow linewidth.
• Produced a nearly diffraction-limited far-field lobe.
• Obtained an overall gain of 25 dB with 290 mW locked output under small-signal input conditions.

Conclusions:

• The demonstrated multistage diode-array injection-locking technique effectively enhances power extraction and overall gain.
• This approach offers a viable solution for generating high-power, spectrally pure laser output from diode arrays.
• The results indicate significant improvements over conventional single-stage designs.