Surface-Emitting Laser Stack for Temperature-Stable Emission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional surface emitting lasers experience unstable light emission characteristics due to temperature-dependent changes in driving temperature, leading to variations in oscillation wavelength and gain, which affects the emission spectrum.
Innovation Solution
A surface emitting laser design featuring multiple active regions with different peak emission wavelengths, thicknesses, and numbers of active layers, along with strategically placed tunnel junctions, to stabilize emission characteristics across varying temperatures by ensuring consistent current injection and reduced light absorption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple active regions with different peak wavelengths are stacked, then emission characteristics can be stabilized across temperature changes, but device complexity increases due to additional layers and tunnel junctions
Solution Approach 1:
The active region is divided into multiple stacked active regions (first, second, third active regions) with different peak emission wavelengths. Each active region is further segmented into multiple active layers with specific thicknesses and compositions. This segmentation allows the laser to maintain stable emission characteristics across temperature changes by distributing the emission across multiple wavelength regions.
Solution Approach 2:
Multiple active layers are nested within each active region, with the first active region containing multiple active layers, the second active region containing multiple active layers, and the third active region containing multiple active layers. This nested structure enables compact integration of multiple emission wavelengths within a vertically stacked configuration.
Solution Approach 3:
Tunnel junctions are introduced as intermediary elements between adjacent active regions to enable efficient current injection and carrier transport. The tunnel junctions act as mediators that facilitate charge carrier transfer between the different active regions while maintaining electrical isolation and enabling independent optimization of each active region's emission characteristics.
2Reliability
If active regions with varying compositions and thicknesses are used, then temperature stability improves, but manufacturing precision requirements increase
Solution Approach 1:
Each active region is designed with local quality variations - the first active region has specific active layer thicknesses and compositions optimized for its peak wavelength, the second active region has different thicknesses and compositions for its wavelength, and the third active region has yet another configuration. This local quality approach allows each region to be independently optimized for temperature stability while maintaining manufacturability through standardized growth processes.
Solution Approach 2:
The invention systematically varies key parameters across the stacked active regions - active layer thickness (ranging from tens to hundreds of nanometers), indium composition (x in InxGa1-xAs varying between 0.0 and 1.0), and number of active layers (1-10 layers per region). These parameter changes are designed to shift peak emission wavelengths and create temperature-dependent gain profiles that stabilize overall emission characteristics across a wide temperature range.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design stabilizes light emission characteristics across a wider temperature range, reducing light absorption loss and maintaining desired laser performance by aligning peak wavelengths closer to the emission surface and varying active layer properties.
Implementation Method 1
a tunnel junction disposed between at least one set of two adjacent active regions
Data Source
AI summary
The present technology provides a surface emitting laser capable of stabilizing emission characteristics against change in driving temperature.The present technology provides a surface emitting laser including: first and second multilayer film reflectors; a plurality of active regions stacked between the first and second multilayer film reflectors; and a tunnel junction disposed between at least one set of two adjacent active regions, in which the plurality of active regions includes at least two of the active regions in which peak wavelengths of emission spectra are different from each other. According to the present technology, a surface emitting laser capable of stabilizing emission characteristics against change in driving temperature is provided.