Semiconductor Laser Phase Modulation Layout for Uniform Light Output
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Solution Overview
Problem
Semiconductor laser elements experience one-dimensional local oscillation, leading to uneven light intensity distribution and image quality issues such as missing design patterns or blurring due to one-dimensional diffraction and flat band diffraction.
Innovation Solution
The semiconductor laser element is structured with a phase modulation layer having modified refractive index regions arranged in a two-dimensional pattern, where each region's center of gravity is separated from the virtual lattice points, and the Fourier coefficients are set to minimize one-dimensional oscillation by satisfying conditions for Γ-point or M-point oscillation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If modified refractive index regions are arranged in a two-dimensional pattern with center of gravity separated from lattice points, then one-dimensional local oscillation is reduced and light intensity distribution becomes uniform, but device complexity increases due to precise positioning requirements
Solution Approach 1:
The patent applies asymmetry by deliberately offsetting the center of gravity of modified refractive index regions from the lattice points of the virtual square lattice. This asymmetric arrangement breaks the symmetry that causes one-dimensional diffraction and flat band diffraction, thereby reducing one-dimensional local oscillation and achieving more uniform light intensity distribution across the laser beam profile.
Solution Approach 2:
The patent transitions from one-dimensional oscillation patterns to two-dimensional oscillation by arranging modified refractive index regions in a two-dimensional pattern on the reference surface. This dimensional expansion suppresses one-dimensional diffraction effects and enables two-dimensional diffraction, resulting in improved uniformity of light intensity distribution.
2Measurement precision
If Fourier coefficients are optimized to minimize one-dimensional oscillation, then image resolution and quality improve, but manufacturing precision requirements increase
Solution Approach 1:
The patent optimizes specific parameters including the offset distance between center of gravity and lattice points, the size and shape of modified refractive index regions, and the lattice spacing. By carefully controlling these parameters, the Fourier coefficients are optimized to minimize one-dimensional oscillation components, thereby improving image resolution and quality while maintaining feasible manufacturing precision requirements.
3Area of stationary object
If lattice spacing and wavelength satisfy Γ-point or M-point oscillation conditions, then two-dimensional diffraction is enhanced and output area increases, but control difficulty increases
Solution Approach 1:
The patent designs the phase modulation layer structure to achieve multi-functionality: it simultaneously enables Γ-point oscillation and M-point oscillation modes, each providing different diffraction characteristics. This allows the system to enhance two-dimensional diffraction and increase output area while maintaining controllable oscillation characteristics through appropriate mode selection based on application requirements.
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
This structure reduces one-dimensional local oscillation, resulting in uniform light intensity distribution and increased output area in a single mode, thereby improving image resolution and quality.
Implementation Method 1
The phase modulation layer includes a base layer and a plurality of modified refractive index regions. The plurality of modified refractive index regions each has a refractive index different from a refractive index of the base layer
Implementation Method 2
a light-emitting layer and a phase modulation layer provided on the substrate
Data Source
AI summary
A semiconductor laser element of the present disclosure reducing one-dimensional local oscillation includes a substrate, an active layer, and a phase modulation layer. The phase modulation layer includes a base layer and modified refractive index regions two-dimensionally placed on a reference surface. In a virtual square lattice on the reference surface, the gravity center of each modified refractive index region is placed away from the corresponding lattice point, and an angle of a vector connecting the corresponding lattice point to the gravity center is set individually. A lattice spacing and a light emission wavelength of the active layer satisfy a Γ-point oscillation condition. The gravity center of each modified refractive index region is placed such that the absolute value of the Fourier coefficient of an annular or a circular shape obtained by rotating each modified refractive index region with the corresponding lattice point is 0.01 or less.