Optical Semiconductor Device with Short-Circuited Conductive Regions
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Solution Overview
Problem
Conventional optical terminators fail to completely prevent reflected return light, leading to poor performance and absorption saturation issues due to electron-hole pair accumulation without an external electric field, and require external power sources for effective operation.
Innovation Solution
An optical semiconductor device with a light absorbing region sandwiched by conductive regions, where the conductive regions are short-circuited to prevent potential differences and allow electron-hole pairs to be annihilated, maintaining electric field intensity without external power, thus suppressing reflection and absorption saturation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a light absorbing region is used to prevent reflection, then light absorption is improved, but absorption saturation occurs due to electron-hole pair accumulation
Solution Approach 1:
An n-type semiconductor layer is introduced as an intermediary between the light absorbing region and the substrate. This intermediary layer provides a collection path for charge carriers through its depletion layer, preventing electron-hole pair accumulation in the light absorbing region while maintaining effective light absorption. The n-type layer acts as a mediator that transports charge carriers away from the absorption region, resolving the saturation problem.
2Use of energy by moving object
If a PIN diode structure is used to increase light intensity handling, then absorption capacity is improved, but photovoltaic effect lowers electric field intensity
Solution Approach 1:
The invention extracts and removes the p-type semiconductor region from the conventional PIN diode structure, retaining only the n-type semiconductor layer. This extraction eliminates the photovoltaic effect that would otherwise generate potential differences and reduce electric field intensity. The remaining n-type layer with its depletion layer maintains strong electric fields while still providing charge carrier collection capability for high light intensity handling.
3Ease of operation
If a light receiver with external power source is used to separate electron-hole pairs, then charge separation is improved, but device complexity and power consumption increase
Solution Approach 1:
The n-type semiconductor layer automatically generates and maintains its own depletion layer through self-doping, creating an intrinsic electric field without requiring external power sources. The layer serves itself by utilizing its own dopant atoms to create the charge separation mechanism, eliminating the need for external control circuits or power supplies while maintaining effective charge separation capability.
4Object-affected harmful factors
If the waveguide end is inclined to prevent reflection, then reflection is reduced, but reflection prevention is incomplete
Solution Approach 1:
The n-type semiconductor layer serves as an intermediary between the optical waveguide and the substrate, providing a controlled depletion layer that actively manages charge carrier separation. This intermediary structure offers superior reflection prevention compared to simple geometric inclination, as the depletion layer creates an electric field that actively separates charge carriers and prevents reflected light generation, achieving more complete reflection suppression.
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 solution effectively suppresses reflection and maintains optical terminator characteristics even at high light intensities without external power, reducing manufacturing costs and power consumption.
Implementation Method 1
a light absorbing region coupled to the optical waveguide
Implementation Method 2
a conductor coupled to the first conductive region and the second conductive region to let the first conductive region and the second conductive region short-circuit
Implementation Method 3
since the photovoltaic effect generates a potential difference between the P-type semiconductor region and the N-type semiconductor region
Data Source
AI summary
An optical semiconductor device including an optical waveguide; a light absorbing region coupled to the optical waveguide; a first conductive region and a second conductive region disposed at both sides of the light absorbing region so as to sandwich the light absorbing region; and a conductor coupled to the first conductive region and the second conductive region to let the first conductive region and the second conductive region short-circuit. With this configuration, the optical semiconductor device provides effects that absorption saturation is less likely to occur even if the light intensity increases, so that reflection return light can be reliably suppressed without using an external power source.