Optical Semiconductor Device Self-Aligned Light Coupling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing techniques for bonding a semiconductor laser to a silicon waveguide require extremely high accuracy, which reduces productivity in introducing light into the waveguide with high efficiency.
Innovation Solution
An optical semiconductor device with a stacked body that includes a light transmitting portion, where the contact layer is partially exposed to form a waveguide mode only when in optical contact with the waveguide member, allowing for efficient light introduction by concentrating current at the contact region, thereby reducing the assembly accuracy requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If extremely high accuracy bonding is used to introduce light from semiconductor laser into silicon waveguide with high efficiency, then light introduction efficiency is improved, but productivity deteriorates
Solution Approach 1:
The patent changes the electrical parameters of the contact layer by controlling its thickness and material composition. The contact layer is designed with specific thickness (e.g., 10-50 nm) and conductivity to enable waveguide mode formation only when in contact with the waveguide member. This parameter control allows the system to transition between non-waveguide state (during assembly) and waveguide state (during operation), resolving the contradiction between assembly ease and light introduction efficiency
Solution Approach 2:
The contact layer automatically forms a waveguide mode when it comes into contact with the waveguide member, without requiring external alignment adjustments or complex positioning mechanisms. The electrical and optical properties of the contact layer itself enable the light coupling function, making the system self-aligning and eliminating the need for high-precision bonding processes
2Ease of operation
If predetermined light emitting region is used in semiconductor laser, then light emission is controlled, but assembly accuracy requirement increases
Solution Approach 1:
The patent transitions from controlling light emission through spatial positioning (which requires high assembly accuracy) to controlling it through electrical properties of the contact layer. By adjusting the conductivity, thickness, and material composition of the contact layer, the light emission and coupling characteristics are controlled in the electrical dimension rather than the mechanical positioning dimension, thereby reducing assembly accuracy 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 configuration enables easy and efficient light introduction into the waveguide member, improving productivity by allowing self-alignment and reducing the need for high-accuracy assembly, while also increasing optical gain and reducing light leakage.
Implementation Method 1
a light transmitting portion formed by not covering at least part of a surface of the contact layer on a side opposite to the semiconductor substrate with the first electrode
Implementation Method 2
an active layer and a contact layer arranged on a side opposite to the semiconductor substrate with respect to the active layer; a first electrode in contact with the contact layer; and a second electrode formed on the second main surface
Data Source
AI summary
An optical semiconductor device includes: a semiconductor substrate including a first main surface and a second main surface; a stacked body that is formed on the first main surface and includes an active layer and a contact layer arranged on a side opposite to the semiconductor substrate with respect to the active layer; a first electrode in contact with the contact layer; and a second electrode formed on the second main surface. The stacked body includes a light transmitting portion formed by not covering at least part of a surface of the contact layer on a side opposite to the semiconductor substrate with the first electrode. The optical semiconductor device is configured such that a waveguide mode is not formed by current application through the first electrode and the second electrode in a state in which the light transmitting portion is not in optical contact with an external member.