Solid-State Laser Pumping with Incoherent Monochromatic Light
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Solution Overview
Problem
Existing solid-state lasers face inefficiencies in pumping due to limitations of flash lamps and semiconductor diode lasers, including low coupling efficiency, excessive heat generation, short lifetimes, and limited wavelength availability, which restrict their high-power and high-repetition rate operations.
Innovation Solution
A solid-state laser design utilizing incoherent monochromatic light from LED or VCSEL arrays, coupled through a diffusing pump chamber for uniform excitation and efficient heat management, enabling efficient energy delivery and stimulated emission with minimal loss, suitable for various lasing media and operating conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If flash lamps are used to pump solid-state lasers, then high conversion efficiency is achieved, but coupling efficiency is low causing excessive heat generation and thermal effects
Solution Approach 1:
The patent changes the spectral parameters of the pump source by using LED arrays with specific emission wavelengths (405nm, 450nm, 532nm, etc.) that precisely match the absorption bands of the laser gain medium. This spectral parameter optimization enables both high conversion efficiency and high coupling efficiency simultaneously, eliminating the heat generation problem associated with flash lamps.
2Loss of energy
If semiconductor diode lasers are used for pumping, then high coupling efficiency is achieved, but peak power is limited and device is vulnerable to damage
Solution Approach 1:
The patent divides the pump source into multiple independent LED arrays, each operating at different wavelengths (405nm, 450nm, 532nm, etc.). This segmentation allows each LED array to contribute to the overall pumping without requiring any single device to operate at excessively high peak powers, thereby maintaining high coupling efficiency while avoiding the vulnerability to damage associated with high-power diode lasers.
3Ease of operation
If side-pumping configuration is used, then pumping is achieved, but mode-pump overlap is inefficient leading to hot spots and beam quality degradation
Solution Approach 1:
The patent transitions from traditional side-pumping (lateral dimension) to end-pumping configuration where LED arrays are positioned at the ends of the laser gain medium along the optical axis. This dimensional change enables uniform pump distribution throughout the gain medium volume, achieving both effective pumping and excellent mode-pump overlap without hot spots or beam quality degradation.
4Ease of operation
If flash lamps are used, then pumping is achieved, but operating lifetime is short requiring frequent replacement
Solution Approach 1:
The patent replaces the expensive, short-lived flash lamp with LED arrays that offer both extended operational lifetime (50,000-100,000 hours) and lower cost. The LED-based pump sources eliminate the need for frequent replacements while maintaining reliable pumping function, directly addressing the reliability and operational continuity requirements.
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 design achieves a compact, robust, and cost-effective laser capable of sustained high-power operation over wide temperature ranges with low power consumption and high repetition rates, addressing the limitations of prior technologies.
Implementation Method 1
solid-state lasers pumped by incoherent monochromatic light sources such as light emitting diode(s) (LEDs)
Implementation Method 2
incoherent monochromatic light from LED or VCSEL arrays
Implementation Method 3
coupled through a diffusing pump chamber for uniform excitation
Implementation Method 4
efficient energy delivery and stimulated emission with minimal loss
Data Source
AI summary
Solid-state laser(s) pumped by incoherent, monochromatic light from sources such as LED arrays and integrating technologies such as high power LED arrays and solid-state laser materials in conjunction with efficient and uniform absorption of pumping energies through a diffusing pump chamber. The resulting laser(s) are compact, robust, low-cost, and able to produce high power output for practical applications. It may efficiently operate over wide temperature and performance ranges, at CW or pulse modes, even with ultra short pulse width and/or extremely high repetition rates. Our inventive structure(s) is/are highly flexible and applicable to a large group of lasing media including those with very short upper state life times. Advantageously, they may be applied to a plethora of laser systems at wavelengths that have important applications and unavailable to other direct pumping technologies.