Planar Pulse Duration Measurement Without Laser Beam Branching
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Solution Overview
Problem
Conventional pulse duration measuring apparatuses for pulsed laser beams are cumbersome and time-consuming due to the need for branching a laser beam from the laser processing apparatus for measurement.
Innovation Solution
A compact, planar pulse duration measuring apparatus with optical components disposed on a planar surface, including a laser beam entry element, polarizing beam splitter, mirrors, quarter wavelength plates, optical path length changing unit, nonlinear crystal body, and photodetector, which can be directly placed on the chuck table of a laser processing apparatus to measure pulse duration without branching the laser beam.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional pulse duration measuring apparatus is used to measure the pulse duration of a pulsed laser beam, then the measurement can be performed, but the apparatus is large in size, requires beam branching from the laser processing apparatus, and is tedious and time-consuming to install and adjust
Solution Approach 1:
The patent transitions from a three-dimensional bulky apparatus to a two-dimensional planar configuration. All optical components (beam splitter, mirrors, quarter-wave plates, nonlinear crystal, photodetector) are arranged on a single planar surface, allowing the measurement apparatus to be compact and easily integrated into the laser processing system without requiring complex spatial arrangements.
Solution Approach 2:
The patent combines multiple optical components that were previously separate in conventional apparatuses into a single integrated planar structure. The beam splitter, mirrors, quarter-wave plates, nonlinear crystal body, and photodetector are all disposed on the same planar surface, merging their functions into a compact unified system that eliminates the need for separate beam branching apparatus.
2Measurement precision
If a conventional pulse duration measuring apparatus is used, then pulse duration can be measured, but it requires branching the laser beam from the laser processing apparatus, which adds installation and adjustment time
Solution Approach 1:
The patent extracts the essential measurement function from the complex conventional apparatus and implements it directly on the planar surface where the laser beam is already present. By using a beam splitter to separate a portion of the existing laser beam and arranging all measurement components on the same plane, the system eliminates the need for separate beam branching apparatus and reduces installation complexity.
Solution Approach 2:
The planar configuration allows the measurement apparatus to be self-contained and self-adjusting. All optical components are disposed on a single planar surface, creating a compact system that automatically aligns with the laser beam path without requiring extensive external adjustment mechanisms or complex installation procedures.
3Measurement precision
If a conventional pulse duration measuring apparatus is used, then measurement can be performed, but the apparatus is relatively large in size requiring more space
Solution Approach 1:
The patent reduces the spatial footprint by transitioning from a three-dimensional volumetric arrangement to a two-dimensional planar configuration. All optical components are arranged on a single planar surface, compressing the apparatus into a thin profile that occupies minimal space while maintaining full measurement functionality.
Solution Approach 2:
By merging all optical components (beam splitter, mirrors, quarter-wave plates, nonlinear crystal, photodetector) onto a single planar surface, the patent creates a compact integrated system. This consolidation eliminates the need for multiple separate components distributed in three-dimensional space, dramatically reducing the overall apparatus footprint.
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
The apparatus efficiently measures pulse duration by eliminating the need for beam branching, reducing installation and adjustment time, and providing accurate pulse duration measurements directly on the laser processing apparatus.
Implementation Method 1
a polarizing beam splitter for splitting the pulsed laser beam from the laser beam entry element into a first laser beam traveling along a first optical path and a second laser beam traveling along a second optical path
Implementation Method 2
a first quarter wavelength plate disposed between the polarizing beam splitter and the first mirror, a second quarter wavelength plate disposed between the polarizing beam splitter and the second mirror
Implementation Method 3
a first mirror for reflecting the first laser beam traveling along the first optical path toward the polarizing beam splitter, a second mirror for reflecting the second laser beam traveling along the second optical path toward the polarizing beam splitter
Implementation Method 4
a nonlinear crystal body for allowing a combined laser beam to pass therethrough, the combined laser beam including respective returning laser beams of the first and second laser beams reflected respectively by the first and second mirrors and combined by the polarizing beam splitter
Implementation Method 5
a photodetector for measuring an optical intensity of the combined laser beam that has passed through the nonlinear crystal body
Data Source
AI summary
A pulse duration measuring apparatus includes a polarizing beam splitter for splitting a pulsed laser beam into a first laser beam and a second laser beam, a first mirror for reflecting the first laser beam traveling toward the polarizing beam splitter, a second mirror for reflecting the second laser beam traveling toward the polarizing beam splitter, a first quarter wavelength plate disposed between the polarizing beam splitter and the first mirror, a second quarter wavelength plate disposed between the polarizing beam splitter and the second mirror, an optical path length changing unit for moving the first mirror or the second mirror to change the length of the respective optical paths, a nonlinear crystal body for allowing a combined laser beam to pass therethrough, and a photodetector for measuring an optical intensity of the combined laser beam that has passed through the nonlinear crystal body.