Scanning Probe Microscope Laser Spot Adjustment
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Solution Overview
Problem
In scanning type probe microscopes, manual optical axis adjustment of laser light is difficult and time-consuming due to the small size of the cantilever, making it challenging to automatically adjust the laser beam spot when it cannot be detected by the optical microscope or CCD-imaging unit, leading to complex and inefficient operation.
Innovation Solution
A scanning type probe microscope with an optical system that adjusts the laser light spot diameter to be larger than when measuring samples, incorporating an imaging unit to capture images, an image processing unit to specify the laser light spot position, and an optical axis adjustment unit to automatically adjust the laser light based on the specified position, allowing for precise alignment of the laser beam.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the spot diameter of laser light is kept small for precise measurement, then measurement precision is improved, but the laser spot becomes undetectable by the optical microscope or CCD-imaging unit, making automatic optical axis adjustment impossible
Solution Approach 1:
The patent applies dynamics by making the spot diameter adjustable rather than fixed. The laser light spot diameter is dynamically changed between two states: a small diameter during measurement for precision, and a large diameter during optical axis adjustment for detectability. This dynamic adaptation allows the system to optimize for different operational requirements without compromise.
Solution Approach 2:
The patent directly applies parameter changes by modifying the spot diameter parameter of the laser light. During optical axis adjustment, the spot diameter is increased to make the laser spot detectable by the imaging unit. During measurement, the spot diameter is reduced to achieve precise measurement. This parameter transformation resolves the contradiction between detectability and measurement precision.
2Manufacturing precision
If manual optical axis adjustment is performed, then the laser light can be aligned with the cantilever, but the process becomes difficult and time-consuming due to the small size of the cantilever
Solution Approach 1:
The patent implements feedback by using the imaging unit to detect the position of the laser spot and providing this information back to the control device. The control device then automatically adjusts the laser light source or optical components based on this feedback to achieve proper alignment. This closed-loop feedback system eliminates the need for difficult manual adjustment while maintaining high precision.
Solution Approach 2:
The patent replaces the manual mechanical adjustment system with an automatic optical-detection-based system. Instead of relying on operators to visually locate and manually position the laser spot on the tiny cantilever, the system uses the imaging unit to detect the laser spot position and automatically controls the adjustment, substituting mechanical manual operation with automated optical-mechanical integration.
3Difficulty of detecting and measuring
If the spot diameter is increased for easier detection during adjustment, then the laser spot becomes visible in the captured image, but the measurement precision deteriorates
Solution Approach 1:
The patent applies dynamics by making the spot diameter adjustable rather than fixed. The laser light spot diameter is dynamically changed between two states: a small diameter during measurement for precision, and a large diameter during optical axis adjustment for detectability. This dynamic adaptation allows the system to optimize for different operational requirements without compromise.
Solution Approach 2:
The patent directly applies parameter changes by modifying the spot diameter parameter of the laser light. During optical axis adjustment, the spot diameter is increased to make the laser spot detectable by the imaging unit. During measurement, the spot diameter is reduced to achieve precise measurement. This parameter transformation resolves the contradiction between detectability and measurement precision.
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
Facilitates easy and efficient optical axis adjustment of the laser light, increasing the probability of detecting the laser spot and enabling automatic alignment, thereby simplifying the operation and improving the accuracy of measurements.
Implementation Method 1
The deflection or the change in the vibration of the cantilever is converted into a change in the reflected light of the laser irradiated on the rear surface of the cantilever and detected by a photodetector
Data Source
AI summary
A cantilever has a probe at a tip end. An optical system emits laser light to the cantilever and detects the laser light reflected by the cantilever. A measurement unit measures characteristics of a sample based on a displacement of the cantilever obtained by a change in a position of the laser light detected by the optical system. The laser light adjustment unit adjusts, when adjusting the optical axis of the laser light, a spot diameter of the laser light to be larger than the spot diameter when measuring the characteristics of a sample. The imaging unit captures an image of a range including the position of the probe when adjusting the optical axis of the laser light. The display unit displays the captured image.