Removable Heater Athermalized Optical Mount
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for permanently aligning optical elements in laser apparatus, such as solder-bonding with a PCT, are costly due to the need for multiple PCTs and require careful selection of materials for thermal expansion compatibility, and can result in misalignment from shear forces and excessive heating during the alignment process.
Innovation Solution
A base-plate with a pedestal having spaced-apart legs and a heatable platform supports an element-holding member with a solder layer, allowing for alignment by softening the solder with a removable heat-source, such as an electric cartridge heater, which can be reused and reduces thermal stress through flexible leg attachment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a PCT thermistor is used for heating the solder during alignment, then the solder can be softened for precise alignment, but the PCT remains in the mount after alignment completing causing increased cost and device complexity
Solution Approach 1:
The heating element is extracted from the permanent mount structure and replaced with a removable cartridge heater. The cartridge heater can be inserted temporarily during alignment to soften the solder, then removed after alignment is complete. This eliminates the PCT thermistor from the final mount structure, reducing device complexity and cost while maintaining alignment precision during the manufacturing process.
Solution Approach 2:
The alignment operation is performed as a preliminary action before final assembly. The cartridge heater is used temporarily during this preliminary alignment phase to soften the solder, allowing precise positioning of the optical element. Once alignment is complete, the heater is removed and the solder solidifies, locking the element in place without requiring the heater to remain in the final structure.
2Reliability
If two solder bonds are required in the mount, then the optical element can be securely attached, but the manufacturing cost and process complexity increase
Solution Approach 1:
The mount structure is segmented into a pedestal portion and a bridge portion connected by legs. This segmentation allows the optical element to be attached to the pedestal with one solder bond, while the bridge portion with the cartridge heater attaches to the base plate with another solder bond. The segmentation enables independent optimization of each bonding location and simplifies the alignment process by providing a stable pedestal for element attachment.
3Stability of the object's composition
If careful selection of metal parts is required for CTE matching, then thermal expansion compatibility is achieved, but the material selection process becomes more complex and time-consuming
Solution Approach 1:
Different material properties are optimized for different locations in the mount structure. The pedestal portion, which directly supports the optical element, is made of a material with CTE matched to the optical element for local thermal compatibility. The bridge portion and legs can use different materials optimized for their specific functions, such as mechanical strength or thermal conductivity, without requiring overall CTE matching across the entire structure. This local optimization reduces material selection complexity while maintaining thermal stability where it matters most.
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 solution reduces costs by reusing the heating element, minimizes thermal expansion mismatch, and decreases heating and cooling times, while maintaining precise alignment with reduced shear forces and heat transfer, allowing for efficient and flexible optical element mounting.
Implementation Method 1
The platform-portion of the pedestal is temporarily heatable by a removable heat-source to soften the solder layer
Implementation Method 2
The optical element is bonded on a pedestal attached to the PCT and which can be aligned when the solder is soft. Once the alignment is complete, current to the PCT is cut off and the solder solidifies
Data Source
AI summary
A mounting fixture for mounting an optical element on a base-plate has spaced-apart parallel legs attachable by brackets to the base-plate and a mounting platform attached to the legs. The platform can be heated by a removable heater. The optical element is held in a mounting tab attached to the platform by a solder-pad. Heating the platform softens the solder-pad allowing the tab and the element to be aligned. Removing the heat allows the pad to harden to complete the attachment and retain the alignment of the element on the mount.