In this paper, the finite element analysis method is used to simulate the heat dissipation effect of the water-cooling channel in a conical mirror when high power laser (104 W level) is irradiated on it. Several important factors affecting the heat dissipate, such as the inlet flow velocity, loaded laser power and the mirror material, are analyzed systematically. The temperature distribution of the conical mirror with the parameters’ variation is obtained, and the relationship between the above parameters and the temperature results are discussed. Finally, based on the thermal analysis of the water-cooling channel structure of the conical mirror under high power laser, we can find that the water-cooling channel structure can greatly improve the cooling capacity and effectively achieve heat dissipation of the conical mirror.
At present, the finite element method is often used to analyze the thermal effect of laser medium in solid-state lasers. By calculating the temperature field distribution, further research on thermal lens, thermally induced depolarization and other thermal effects can be carried out. In the thermal analysis model of laser medium based on heat conduction equation, the definition and selection of characteristic parameters have an important influence on the calculation results. Due to the difference and diversity in the definition and selection of characteristic parameters, this paper focuses on the definition of heat source in the model, gives the expression of heat source under different spatial distribution of pump light, analyzes definition of conversion coefficient of pump energy into heat deposition in crystal, and limits the range in boundary conditions. Taking the thin disk laser medium as an example, the influence of the model parameters on the calculation results is analyzed and the accuracy of the model is verified compared with the test results.
In order to achieve the uniform picosecond laser micro-machining effect, this study carries out the research of shaping the original incident Gaussian beam into a micron-level flat-top beam at the focal position. Based on the principle of diffractive optics, the phase distribution of the shaping element is calculated which meets the micron-level flat-top beam output requirements and the verification of the shaping effect after transforming through the phase distribution is simulated. When the simulated output beam distribution meets the design requirements, the shaping elements is manufactured. Finally, the shaping element is used in a picosecond laser micro-scribing experiment and the scribing effect is analyzed. The final experimental results show that the picosecond laser micro-scribing test is carried out with the shaped flat-top beam, and the uniform scribing effect is obtained which satisfies the design requirements.
In this paper, a 15-direction ring laser diode array is chosen as pumping source in order to get uniform pump in laser medium. The diameter of laser rod is 15mm for obtaining high output laser energy. A numerical model of the side-pump pulsed Nd:YAG laser amplifier is set up. The finite element method using Ansys software is adopted to analyze the time-varying thermal effect. In order to find the temperature influence of the pump light’s distribution, the temperature distributions in laser rod loaded by 15-direction Gaussian beam and simplified uniform beam are calculated and the results are comparatively analyzed. Despite the highest temperature in laser rod is different, the whole variation trend is similar which indicates time-varying characteristic. The thermal lens effect is also calculated and the results indicate that the temperature gradient in the medium plays the most important role. This study could provide a simulation tool to evaluate the thermal effect of the laser amplifier.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.