Semiconductor Laser Drive Electrode Asymmetry for Noise Reduction
Solution Overview
Problem
Conventional semiconductor laser devices are unable to perform wavefront control, preventing the formation of variable desired laser beam patterns due to the presence of noise light.
Innovation Solution
A semiconductor laser device is developed by overlaying a semiconductor laser chip with a spatial light modulator, featuring a drive electrode with a non-periodic structure to prevent noise light interference, allowing for phase control and modulation of laser beams to form desired patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a periodic structure is used in the drive electrode, then the manufacturing is simplified, but noise light is generated due to interference of laser beams
Solution Approach 1:
The drive electrode uses a non-periodic asymmetric structure instead of a periodic symmetric structure. The opening positions and sizes are deliberately designed to be non-uniform, which prevents constructive interference of laser beams and eliminates noise light generation while maintaining manufacturing feasibility through standard photolithography processes.
2Adaptability or versatility
If wavefront control is implemented using a spatial light modulator, then variable laser beam patterns can be formed, but noise light from the drive electrode interferes with the beam quality
Solution Approach 1:
The non-periodic asymmetric structure of the drive electrode prevents regular interference patterns, allowing the spatial light modulator to achieve clean wavefront control without noise light contamination. This enables high-quality variable laser beam patterns including annular beams for optical tweezers applications.
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 device effectively reduces noise light and enables the formation of variable laser beam patterns, enhancing its applications in imaging and hologram design.
Implementation Method 1
a diffractive grating layer optically coupled to the active layer
Implementation Method 2
modulates a laser beam output along a thickness direction of the semiconductor laser chip by the spatial light modulator
Data Source
AI summary
This semiconductor laser device includes a semiconductor laser chip and a spatial light modulator SLM optically coupled to the semiconductor laser chip. The semiconductor laser chip LDC includes an active layer 4, a pair of cladding layers 2 and 7 sandwiching the active layer 4, a diffraction grating layer 6 optically coupled to the active layer 4, and a drive electrode E3 that is disposed between the cladding layer 2 and the spatial light modulator SLM and supplies an electric current to the active layer 4, and the drive electrode E3 is positioned within an XY plane and has a plurality of openings as viewed from a Z-axis direction and has a non-periodic structure.