Class of resonator for slab waveguide lasers.

Area of Science:

• Optics and Photonics
• Laser Physics
• Semiconductor Lasers

Background:

• Higher-order lateral modes in slab waveguide lasers often suffer from poor beam quality and inefficient outcoupling.
• Existing resonator designs may not effectively stabilize or collimate these modes for practical applications.

Purpose of the Study:

• To introduce and analyze a new laser resonator design incorporating a feedback collimator (FBC).
• To demonstrate the FBC resonator's capability to mode-match feedback onto higher-order lateral modes.
• To evaluate the FBC resonator's effectiveness in producing a high-quality, laterally collimated output beam.

Main Methods:

• Development of design principles for the feedback collimator (FBC) resonator.
• Construction and testing of both refractive and reflective FBC resonator configurations.
• Comparative analysis of FBC resonators against angled-ridge resonators using broad-ridge quantum cascade lasers.

Main Results:

• The FBC resonator successfully mode-matches feedback onto higher-order lateral modes.
• The resonator converts stabilized modes into laterally collimated output beams exceeding twice the laser-active region width.
• Initial comparisons indicate potential advantages in efficiency and threshold characteristics for the FBC design.

Conclusions:

• The FBC resonator offers a promising approach for enhancing the beam quality and output characteristics of slab waveguide lasers.
• This design facilitates the generation of high-quality, wide-aperture beams from higher-order modes.
• Further investigation and optimization of FBC resonators are warranted for advanced laser applications.