Simple design of an edge-emitting diode laser for preventing spatial multimoding via thermal lensing

Area of Science:

• Semiconductor diode lasers
• Optoelectronics
• Photonics

Background:

• Achieving stable, single-spatial-mode operation in diode lasers at high continuous-wave (CW) powers is critical for many applications.
• Existing designs often struggle with mode instability and reduced output power at higher drive levels.

Purpose of the Study:

• To numerically determine the optimal parameters for a diode-laser structure.
• To enable stable, single-spatial-mode operation at high CW output powers.

Main Methods:

• Implementation of a three-dimensional numerical code incorporating carrier diffusion in the quantum well and thermal lensing effects.
• Calculation of laser characteristics as a function of the above-threshold drive level.
• Computation of higher-order optical modes using the Arnoldi algorithm on a "frozen background".

Main Results:

• Numerical simulations identified key parameters for diode-laser structures.
• Stable single-mode operation up to multiwatt-level (2-3 W) CW output power is predicted for devices with a 6-μm-wide low-index core and 2-3 mm length.
• The model accounts for complex physical phenomena like carrier diffusion and thermal lensing.

Conclusions:

• The study successfully identified design parameters for high-power, stable single-mode diode lasers.
• The numerical approach provides a reliable method for optimizing diode-laser performance.
• The findings pave the way for developing more efficient and powerful semiconductor laser sources.