Beam Splitter Reflection Suppression for Lower PDL and WDL
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional beam splitters introduce polarization dependent loss (PDL) and waveguide dispersion loss (WDL) due to light reflection, affecting the polarization state and transmission efficiency.
Innovation Solution
A beam splitter design incorporating a beam-splitting layer, anti-reflective layer, and reflection suppression layer to minimize light reflection, using a Non-Polarizing Reflector (NPR) film and diffuse or light-absorbing materials to suppress reflected light rays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a traditional large-angle beam splitter is used to divide light beams, then beam-splitting function is achieved, but polarization dependent loss (PDL) and waveguide dispersion loss (WDL) are introduced due to light reflection
Solution Approach 1:
The harmful reflected light is extracted and separated from the main optical path by positioning the reflection suppression layer on a reflection path that is offset from the main optical axis, allowing the reflected light to be directed to a separate monitoring path rather than re-entering the waveguide
Solution Approach 2:
The anti-reflective layer serves as an intermediary element between the beam-splitting layer and the incident light, reducing the intensity of reflected light before it reaches the reflection suppression layer, thereby minimizing PDL and WDL in the main optical path
2Loss of energy
If an anti-reflective layer is added to reduce light reflection, then reflection is reduced, but reflected light rays still need to be suppressed to prevent interference
Solution Approach 1:
The reflected light that would normally be harmful interference is converted into a useful signal for optical power monitoring by directing it to a monitoring photodetector, allowing the reflection to be measured and used for system characterization and control
Solution Approach 2:
The optical path is segmented into a main optical path for signal transmission and a separate reflection path for monitoring, allowing independent optimization of each path without mutual interference
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
Reduces polarization dependent loss and waveguide dispersion loss, enhancing beam-splitting efficiency and reducing interference from reflected light rays.
Implementation Method 1
a beam splitter is generally made of optical glass or an optical thin film, light reflection is inevitable during use of the beam splitter
Implementation Method 2
a beam splitter is an optical element for dividing a light beam into light beams of different wavelengths or directions
Implementation Method 3
the anti-reflective layer is located on a side of an exiting surface of the beam splitter, and configured to reduce light reflection of incident light rays entering the beam splitter
Implementation Method 4
the reflection suppression layer is a diffuse reflection layer
Implementation Method 5
the reflection suppression layer is a light-absorbing layer
Data Source
AI summary
The present disclosure provides a beam splitter, comprising a beam-splitting layer, an anti-reflective layer and a reflection suppression layer; the beam-splitting layer is located on a side of incident surface of the beam splitter, and configured to change an optical path of a part of the incident light rays; the anti-reflective layer is located on a side of exiting surface of the beam splitter, and configured to reduce light reflection of incident light rays entering the beam splitter; and the reflection suppression layer is located on a reflection path of reflected light rays that are reflected by the anti-reflective layer, and configured to suppress the reflected light rays that are reflected by the anti-reflective layer.