Transmissive Optics Fabrication With Ultrashort-Pulse Laser Ablation
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Solution Overview
Problem
Existing methods for manufacturing transmissive optical systems, such as lenses, are inefficient and costly, particularly when dealing with softer materials, as they require multiple iterative steps and are not suitable for precise processing of materials sensitive to temperature.
Innovation Solution
A method utilizing ultra-short pulse duration ablative lasers for precise material ablation and polishing, allowing for the processing of plastics and other sensitive materials with minimal thermal damage, enabling the creation of lenses with density gradients and multi-material compositions for customized refractive behavior.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional laser processing methods are used on softer materials, then material ablation can be achieved, but thermal damage occurs and multiple iterative steps are required
Solution Approach 1:
The patent employs ultra-short pulse laser processing where the laser operates in pulsed mode with pulse durations of picoseconds to nanoseconds. The periodic pulsed action allows the material to be processed before heat can diffuse to surrounding areas, preventing thermal damage while achieving precise ablation of softer materials
Solution Approach 2:
The patent changes the temporal parameter of laser pulse duration to ultra-short scales (picoseconds to nanoseconds). This parameter change transforms the heating mechanism from continuous thermal conduction to transient thermal effects, enabling precise material removal without the thermal damage associated with conventional longer-pulse laser processing
2Manufacturing precision
If multiple iterative processing steps are used, then manufacturing precision can be improved, but productivity decreases and costs increase
Solution Approach 1:
The patent combines multiple processing functions (ablation, smoothing, and polishing) into a single integrated ultra-short pulse laser processing step. By merging these traditionally separate iterative steps into one process using ultra-short pulses, the patent achieves both high manufacturing precision and improved productivity without requiring multiple sequential operations
Solution Approach 2:
The patent enables continuous processing by eliminating the need for intermediate steps between ablation and polishing. The ultra-short pulse laser continuously removes material and smooths surfaces in an uninterrupted sequence, maintaining useful action throughout the process rather than requiring pauses for material replacement or process changes
3Loss of substance
If conventional laser processing is used on temperature-sensitive materials, then material removal is achieved, but the material structure is damaged
Solution Approach 1:
The patent uses ultra-short pulse durations (picoseconds to nanoseconds) to rush through the material processing so quickly that heat cannot diffuse to surrounding areas. This skipping approach allows material ablation to occur before thermal damage can affect the material structure, preserving the integrity of temperature-sensitive materials while achieving precise removal
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
Enables rapid, cost-effective, and precise manufacturing of lenses with reduced curvature, allowing for flexible designs that can be folded and inserted through small openings, while achieving high precision and minimizing light refractions and reflections.
Implementation Method 1
A method utilizes ultra-short pulse duration ablative lasers for precise material ablation and polishing
Implementation Method 2
The material ablation is achieved by direct vaporization and thus the treated material is hardly damaged
Implementation Method 3
The ultra-short laser pulses with durations ranging from a few femtoseconds to a few picoseconds or nanoseconds enable new processing methods that are not possible with conventional tools. These laser flashes lead to extremely high peak intensities, which can be achieved with relatively low pulse energies by virtue of the strong temporal compression
Data Source
AI summary
In a method for the manufacture of a transmissive optical system from a blank, material ablation is achieved on the blank with an ablative laser, and the pulse duration of the ablative laser is less than 1 ns, and preferably lies between 3 fs and 100 fs, or between 100 fs and 10 ps.