Acousto-Optic Laser Modulation for Stable High-Power Output
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional laser apparatuses using acousto-optic modulators within a resonator suffer from reduced laser output power due to the lower light-resisting strength of these modulators, leading to intensity reduction and output power fluctuations.
Innovation Solution
A laser apparatus is designed with an acousto-optic modulation unit comprising a first and second acousto-optic modulator, where the propagation direction of the ultrasonic waves relative to the diffracted beams is differently oriented to reduce frequency shifts, and an amplifier is used to enhance the laser output power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If acousto-optic modulators are disposed within the resonator to reduce frequency shift and output power fluctuation, then output power stability is improved, but laser output power is reduced due to lower light-resisting strength
Solution Approach 1:
The patent extracts the acousto-optic modulators from the resonator and places them outside. This allows the modulators to perform their frequency-stabilizing function without being constrained by the resonator's intensity requirements, thereby resolving the contradiction between output power stability and laser output power.
Solution Approach 2:
The patent segments the laser system into distinct functional modules: the resonator for generating high-power laser beams and the acousto-optic modulation unit for frequency stabilization. This separation allows each component to optimize its function independently, resolving the contradiction between power and stability.
2Reliability
If intensity of laser beam entering the resonator is reduced to match acousto-optic modulator's light-resisting strength, then the modulator can operate within the resonator, but the outgoing beam has reduced intensity
Solution Approach 1:
The modulator is extracted from the resonator's high-intensity beam path and placed in a separate modulation unit. This allows the resonator to maintain high beam intensity for powerful output while the modulator operates at lower intensities suitable for its light-resisting strength, resolving the contradiction between operational stability and beam intensity.
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 configuration reduces output power fluctuations and increases laser output power, stabilizing the beam and enabling higher-quality and faster laser machining by canceling out frequency shifts and minimizing thermal lens effects.
Implementation Method 1
An acousto-optic modulator uses a material having a property of changing its refractive index when vibrated by an ultrasonic wave and is thus an element utilized as a diffraction grating
Implementation Method 2
A diffracted beam that is output by the acousto-optic modulator has a frequency shifted by the frequency of the ultrasonic wave due to the Doppler effect
Data Source
AI summary
A laser apparatus includes a laser oscillator; an acousto-optic modulation unit including a first acousto-optic modulator that diffracts a laser beam from the laser oscillator when a first ultrasonic wave is applied and a second acousto-optic modulator that diffracts a higher order beam output from the first acousto-optic modulator when a second ultrasonic wave is applied; and an amplifier that amplifies the laser beam from the acousto-optic modulation unit, a propagation direction of the first ultrasonic wave relative to a diffracted direction of the higher order beam emitted from the first acousto-optic modulator and a propagation direction of the second ultrasonic wave relative to a diffracted direction of a higher order beam emitted from the second acousto-optic modulator being different.