Lateral waveguide scanner integration on surface-emitting mid-infrared lasers.

Area of Science:

• Optics and Photonics
• Semiconductor Devices
• Laser Technology

Background:

• Traditional laser scanners often rely on mechanical components, limiting miniaturization and robustness.
• Mid-infrared (MIR) laser sources are crucial for various applications, including spectroscopy and free-space communications.
• Integrating beam steering capabilities directly into semiconductor lasers offers a path towards compact and efficient optical systems.

Purpose of the Study:

• To propose and theoretically investigate a novel monolithic, non-mechanical semiconductor laser scanner operating in the mid-infrared (MIR) spectrum.
• To demonstrate the feasibility of integrating an optical phased array (OPA) scanner into GaSb-based surface-emitting interband cascade lasers (SE-ICLs).
• To provide a practical solution for fabricating compact, steerable MIR laser sources.

Main Methods:

• A deflector at the substrate side couples vertical light into a lateral substrate waveguide, forming a chain of coherent emitters (OPA).
• Numerical simulations were performed using GaSb-based SE-ICLs as the platform.
• Analysis of optical path difference and emitter gap to determine beam steering characteristics.

Main Results:

• GaSb-based SE-ICLs are identified as an excellent platform for waveguide scanner integration.
• An extremely high angle tuning coefficient of 0.84°/nm was achieved.
• The proposed device covers a full 28.6° steering range.

Conclusions:

• The theoretical feasibility of integrating an OPA scanner into GaSb-based SE-ICLs is verified.
• This approach offers a practical solution for compact, steerable MIR laser sources.
• The substrate OPA concept shows potential for adaptation to longer wavelength devices (InP, GaAs-based QCLs).