Stable Single-Mode Operation in Surface Emitting Semiconductor Lasers
Here’s PatSnap Eureka !
Summary
Problems
Surface emitting semiconductor lasers with extended cavity structures face challenges in maintaining single-mode operation while increasing oxide aperture diameter, leading to unstable high-power output and mode switching between longitudinal modes.
Innovation solutions
Incorporating a cavity extending region with an optical loss causing layer at specific nodes of standing waves in the extended cavity structure, which increases loss for unnecessary longitudinal modes and reduces loss for the desired mode, thereby suppressing mode switching.
TRIZ Analysis
Specific contradictions:
General conflict description:
Principle concept:
If the oxide aperture diameter is increased to achieve higher optical power, then the power output is improved, but the stability of single-mode operation deteriorates due to switching between longitudinal modes
Why choose this principle:
The patent introduces an optical loss causing layer at specific positions (node positions) within the cavity extending region. This creates local optical loss only at specific locations rather than uniformly throughout the cavity, allowing selective suppression of unwanted longitudinal modes while maintaining the desired mode's oscillation, thus enabling stable single-mode operation at higher powers
Principle concept:
If the oxide aperture diameter is increased to achieve higher optical power, then the power output is improved, but the stability of single-mode operation deteriorates due to switching between longitudinal modes
Why choose this principle:
The patent modifies the cavity structure by extending the cavity length and introducing an optical loss causing layer, which changes the optical parameters of the laser cavity. This alters the loss characteristics for different longitudinal modes, creating a parameter difference that stabilizes single-mode operation even with larger oxide aperture diameters
Application Domain
Data Source
AI summary:
Incorporating a cavity extending region with an optical loss causing layer at specific nodes of standing waves in the extended cavity structure, which increases loss for unnecessary longitudinal modes and reduces loss for the desired mode, thereby suppressing mode switching.
Abstract
A surface emitting semiconductor laser includes: a substrate; a first semiconductor multilayer reflector on the substrate including laminated pairs of a high refractive index layer relatively high in refractive index and a low refractive index layer relatively low in refractive index; an active region on or above the first reflector; a second semiconductor multilayer reflector on or above the active region including laminated pairs of a high refractive index layer relatively high in refractive index and a low refractive index layer relatively low in refractive index; and a cavity extending region formed between the first reflector and the active region or between the second reflector and the active region, having an optical film thickness greater than an oscillation wavelength, extending a cavity length, including a conductive semiconductor material, and including an optical loss causing layer at at least one node of a standing wave of a selected longitudinal mode.