Chip-Scale Circular Polarizer Alignment via Pre-Aligned Dicing
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Solution Overview
Problem
The alignment of the fast axis of a quarter wave plate to a 45-degree angle from the polarizing axis of a linear polarizer is challenging in chip-scale optics systems due to the small size of components, making precise handling and alignment difficult for achieving accurate circular polarization.
Innovation Solution
A method involving a linear polarizer coupled to a quarter wave plate, where the linear polarizer is aligned at a 45-degree angle to form a circular polarizing filter sheet, which is then diced into chip-scale filters with an edge defining a polarization location index for easy alignment with a laser, and positioned within a frame to ensure accurate circular polarization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If chip-scale optics components are used to reduce system size, then miniaturization is achieved, but alignment precision deteriorates due to difficulty in physically handling and measuring very small components
Solution Approach 1:
The patent applies preliminary action by pre-aligning the linear polarizer and quarter wave plate at 45 degrees to each other before dicing the combined assembly into chip-scale components. This pre-alignment ensures that the critical angular relationship is established while the components are still large enough to handle accurately, eliminating the need for difficult post-dicing alignment of sub-millimeter components.
Solution Approach 2:
The patent merges the linear polarizer and quarter wave plate into a single aligned assembly before dicing. By combining these two components with predetermined angular alignment and then cutting them together as one unit, the invention ensures that the alignment relationship is preserved in the final chip-scale components without requiring separate alignment of tiny individual parts.
2Manufacturing precision
If traditional alignment methods are used for small components, then alignment can be achieved, but time consumption increases due to difficulty in handling and measuring very small components
Solution Approach 1:
The invention performs the alignment action beforehand when components are still large and easy to manipulate. By aligning the polarizer and quarter wave plate at 45 degrees before dicing, the time-consuming alignment process is completed while components are readily handleable, avoiding repeated alignment attempts on tiny diced pieces.
Solution Approach 2:
The patent segments the pre-aligned assembly into multiple chip-scale components through dicing. By cutting the already-aligned combined structure into smaller pieces, each piece inherits the predetermined angular relationship, eliminating the need for time-consuming alignment of each individual small component.
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 approach enables quick and accurate alignment of the polarization axes, facilitating the production of chip-scale circular polarizing filters that maintain beam throughput and reduce the need for additional neutral density filters, enhancing the efficiency of precision imaging and measurement systems.
Implementation Method 1
A quarter wave plate may be placed after a linear polarizer to obtain such a circular polarizer, with a fast axis of the quarter wave plate aligned at a 45 degree angle from the polarizing axis of the linear polarizer to obtain accurate circular polarization.
Data Source
AI summary
A method is disclosed for manufacturing a chip-scale optics module for an optical interrogator. The method includes aligning a polarization axis of a linear polarizer to an angle of 45 degrees from a fast axis of a quarter wave plate to enable circular polarization of a beam, when a beam is introduced to the linear polarizer, coupling the linear polarizer to the quarter wave plate after the aligning to form a circular polarizing filter sheet and then dicing the circular polarizing filter sheet to obtain a plurality of chip-scale circular polarizing filters. Each of the chip-scale circular polarizing filters is diced to have an edge that defines a polarization location index for the linear polarizer. A linear polarizer plate face of one of the chip-scale circular polarizing filters is then positioned so that the linear polarizer plate face is aligned with and parallel to an output face of a laser, whereby the polarization axis of the linear polarizer is not orthogonal to a polarization axis of the laser. The chip-scale circular polarizing filter is coupled to a frame after the positioning step.