GaSb-based lasers with two-dimensional photonic crystal mirrors

Area of Science:

• Materials Science
• Optoelectronics
• Nanotechnology

Background:

• Gallium Antimonide (GaSb) is a key material for optoelectronic devices.
• Photonic crystals (PhCs) offer unique light manipulation properties.
• Integrating 2D PhCs into GaSb-based devices can enhance performance.

Purpose of the Study:

• To realize and characterize two-dimensional (2D) photonic crystals (PhCs) on the GaSb material system.
• To evaluate the quality and reflectivity of fabricated PhCs.
• To demonstrate the application of these PhCs in GaSb-based ridge waveguide lasers.

Main Methods:

• Fabrication of 2D PhCs using electron cyclotron resonance reactive ion etching with Cl(2)/Ar.
• Characterization of PhCs with varying air fill factors (20%-50%), lattice periods (400-500 nm), and aspect ratios (5:1).
• Integration of PhCs as high reflective back mirrors in GaSb-based ridge waveguide lasers (cavity lengths 200-1100 µm).

Main Results:

• Successful fabrication of 2D PhCs on GaSb with controlled parameters.
• PhCs demonstrated high reflectivity when used as back mirrors in lasers.
• Shortest devices (200 µm cavity length) exhibited low threshold currents (< 12 mA) and high efficiency (0.23 W/A).
• Maximum output power reached nearly 19 mW.

Conclusions:

• The electron cyclotron resonance reactive ion etch process is effective for fabricating 2D PhCs on GaSb.
• The realized 2D PhCs significantly enhance the performance of GaSb-based ridge waveguide lasers.
• This approach is applicable to various future concepts utilizing 2D PhCs on GaSb.