Passive Q-switch Laser Power Density Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional passive Q-switch laser devices face challenges with low excitation efficiency and significant jitter in delay time for laser oscillation, particularly when strong excitation is required, leading to synchronization issues with external controllers or measurement devices.
Innovation Solution
A passive Q-switch laser device incorporating an input and output mirror, a laser gain medium, a saturable absorber, and a power density controller that adjusts the excitation light's power density to ensure the delay time for reaching laser oscillation is shorter than the laser upper energy level lifetime, enhancing excitation efficiency and reducing jitter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If strong excitation is applied to achieve high output power, then output power is improved, but excitation efficiency deteriorates and jitter in delay time increases
Solution Approach 1:
The patent changes the power density parameter of excitation light to be equal to or greater than a specific threshold value. This parameter change enables the delay time to be controlled within a specific range (equal to or shorter than the upper energy level lifetime), thereby improving excitation efficiency while maintaining high output power. The specific parameter change resolves the contradiction by finding the optimal power density level that balances output power and efficiency.
2Power
If strong excitation is applied to achieve high output power, then output power is improved, but jitter in delay time increases
Solution Approach 1:
By changing the power density parameter to be equal to or greater than a specific value, the patent controls the delay time to fall within a specific range (equal to or shorter than the upper energy level lifetime). This parameter control reduces jitter in delay time while maintaining high output power, resolving the contradiction between power output and timing stability.
3Loss of time
If excitation power density is increased to reduce delay time, then delay time is improved, but heat effects become serious
Solution Approach 1:
The patent identifies and applies a specific threshold value for power density that serves as an optimal balance point. By setting the power density equal to or greater than this specific value, the delay time is reduced to within the upper energy level lifetime while avoiding excessive heat generation. This specific parameter threshold resolves the contradiction by finding the precise operating point where time reduction does not cause harmful thermal effects.
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 power density controller achieves high excitation efficiency and minimizes the jitter in delay time for Q-switch oscillation, enabling synchronized operation with external systems and improved output performance.
Implementation Method 1
The saturable absorber absorbs less incident light power when the incident light power gets increased. The saturable absorber absorbs the incident light when the power of the incident light is equal to or less than an absorption saturation threshold value. When the power of incident light reaches or is higher than the saturation absorption threshold value of the saturable absorber, the saturable absorber turns in to a transparent one.
Implementation Method 2
The excited atoms remain at the laser upper energy level during a laser upper energy level life time period τ and then transit to a laser lower energy level after the life time τ followed by fluorescence emission.
Implementation Method 3
with a configuration including not only a gain medium but also a Q-switch element in a resonator, the laser oscillation is controlled by a varied Q-value of the resonator determined by the Q-switch element laser oscillation
Data Source
AI summary
Provided is a passive Q-switch laser device possessing a power density controller (15) making power density of excitation light from an excitation light source (14) equal to or greater than power density so that delay time required for reaching oscillation after start of excitation of a laser gain medium (12) becomes equal to or shorter than a laser upper energy level lifetime of the laser gain medium (12).