Optical Module Alignment with Inclined End Surface
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Solution Overview
Problem
When the end surface of an optical transmission body is inclined, it becomes difficult to align the optical receptacle with respect to the light receiving and emitting elements, leading to a biased tolerance range and decreased coupling efficiency.
Innovation Solution
The optical module and receptacle are designed such that the principal rays of reception and transmission light are close to each other in the optical path, with the first optical surface refracting these rays to approach the central axis of the optical transmission body, thus maintaining alignment and preventing tolerance range bias.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the end surface of optical transmission body is inclined to reduce returning light, then returning light is reduced and light emitting element operation is stabilized, but alignment between optical receptacle and light receiving/emitting elements becomes difficult and coupling efficiency decreases
Solution Approach 1:
The patent introduces a refractive index matching layer as an intermediary between the optical transmission body and the optical receptacle. This layer has a refractive index that is arithmetic mean of the optical transmission body and the optical receptacle, acting as a mediator to reduce refraction at the interface while maintaining the inclined end surface configuration. This resolves the contradiction by enabling stable operation with inclined surface while reducing alignment sensitivity.
Solution Approach 2:
The patent changes the refractive index parameter of the layer between the optical transmission body and optical receptacle to an arithmetic mean value. This parameter change reduces the refraction effect at the interface, allowing the inclined end surface to function properly while maintaining good coupling efficiency and reducing alignment sensitivity.
2Object-generated harmful factors
If the end surface of optical transmission body is inclined to reduce returning light, then returning light is reduced, but light refraction increases and coupling efficiency decreases
Solution Approach 1:
The refractive index matching layer serves as an intermediary that reduces the refraction effect at the interface between the optical transmission body and optical receptacle. By having the refractive index be the arithmetic mean, the layer minimizes energy loss due to refraction while allowing the inclined end surface to effectively reduce returning light.
Solution Approach 2:
The patent converts the potentially harmful refraction effect at the inclined interface into a beneficial arrangement. By carefully selecting the refractive index of the intermediate layer, the refraction is controlled to maintain coupling efficiency while the inclined surface continues to effectively reduce returning light.
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 design effectively prevents the tolerance range from being biased, even when the end surface of the optical transmission body is inclined, thereby stabilizing the operation of the light emitting element and maintaining high coupling efficiency.
Implementation Method 1
the first optical surface refracting these rays to approach the central axis of the optical transmission body
Implementation Method 2
a transmission reflection section for reflecting, toward the second optical surface, the reception light having entered the inside of the optical receptacle through the first optical surface, and transmitting the transmission light having entered the inside of the optical receptacle through the third optical surface
Data Source
AI summary
An optical module of the present invention includes a light receiving element, a light emitting element, an optical transmission body, and an optical receptacle for allowing reception light from an end surface of the optical transmission body to reach the light receiving element and for allowing transmission light from the light emitting element to reach the end surface of the optical transmission body. In the optical module, a principal ray of the reception light and a principal ray of the transmission light between a transmission reflection section and a first optical surface are located close to each other in a direction along an optical path between a second optical surface and the transmission reflection section as compared to an optical module for comparison.