Photonic Crystal Laser Electrode Layout for Uniform Emission
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Solution Overview
Problem
The existing two-dimensional photonic crystal lasers suffer from non-uniform electric current density and light emission intensity distribution due to the positioning of electrodes, leading to inefficiencies in light amplification and emission.
Innovation Solution
The design incorporates a first electrode with an opening and a second electrode projection such that the circumscribed circle of the second electrode is located within the opening, allowing for a protruding periphery, enabling uniform electric current distribution and suppressing light intensity variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a window-shaped electrode is used to allow laser beam emission, then light emission is enabled, but electric current density becomes non-uniform with lower density at the center
Solution Approach 1:
The electrode is designed with spatially varying properties: the peripheral region extends closer to the active layer to increase current density at the edges, while the central region maintains appropriate distance to allow laser beam emission. This local differentiation of electrode characteristics resolves the contradiction between enabling light emission and maintaining uniform current density distribution.
Solution Approach 2:
The electrode structure is extended into the vertical dimension by varying the distance from the active layer across different regions. The peripheral portion is positioned closer to the active layer while the central portion is positioned farther away, creating a three-dimensional electrode configuration that simultaneously achieves both current uniformity and light emission capability.
2Ease of manufacture
If the active layer is disposed close to the mounting surface to improve current distribution, then manufacturing is simplified, but electric current density at the center remains lower than at the periphery
Solution Approach 1:
Rather than uniformly positioning the entire electrode close to the active layer, the invention applies local quality by differentiating electrode regions: the peripheral region is positioned close to increase central current density, while other regions maintain appropriate spacing. This selective positioning achieves current uniformity without requiring complex overall repositioning of the active layer.
3Illumination intensity
If the electrode area is reduced to allow laser beam passage, then light emission is improved, but electric current supply to the center region is insufficient
Solution Approach 1:
The electrode is segmented into functionally distinct regions: a peripheral region that extends close to the active layer to supply electric current to the center area, and a central region that maintains appropriate distance to allow laser beam emission. This segmentation allows each region to optimize its function without compromising the other.
Solution Approach 2:
Different regions of the electrode are赋予 different spatial characteristics relative to the active layer. The peripheral region has the property of being close to the active layer for current supply, while the central region has the property of being farther away for light emission. This local quality differentiation resolves the contradiction between current supply and light emission.
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 configuration achieves a more uniform electric current density and light emission intensity across the active layer, enhancing the light amplification and emission efficiency of the two-dimensional photonic crystal laser.
Implementation Method 1
a two-dimensional photonic crystal layer provided on one face of the active layer, in which modified refractive index regions are periodically and two-dimensionally disposed
Implementation Method 2
The active layer generates light emission with a specific light emission wavelength band upon being supplied with carriers (positive holes, electrons) from the electrode pair
Data Source
AI summary
A two-dimensional photonic crystal laser includes: an active layer; a two-dimensional photonic crystal layer provided on one face of the active layer, in which modified refractive index regions are periodically and two-dimensionally disposed in a base member of a plate shape, the modified refractive index regions having a refractive index different from the refractive index of the base member; and a first electrode and a second electrode provided so as to sandwich the active layer and the two-dimensional photonic crystal layer in a stacking direction; in which the first electrode has an opening, and at least a part of a projection of a circumscribed circle of the second electrode onto the first electrode is located in the opening, and at least a part of periphery of the opening of the first electrode protrudes into the projection.