Pulse laser frequency multiplier with continuously adjustable conversion efficiency and conversion efficiency adjusting method

Abstract

The invention discloses a pulse laser frequency multiplier with continuously adjustable conversion efficiency and an adjusting method. The pulse laser frequency multiplier comprises a beam expanding / shrinking telescope composed of three lenses, two diaphragms, an optical guide rail with distance scales, lantern rings used for fixing the lenses and the diaphragms to the guide rail, a support, a sliding block and a frequency doubling crystal. According to the method described by the invention, the power density of the laser incident to the frequency doubling crystal can be adjusted by continuously adjusting the size of a laser spot through the telescope, so that the frequency doubling conversion efficiency of the crystal can be adjusted. The frequency doubling efficiency can be continuously adjusted under the condition that crystals with different thicknesses do not need to be replaced, and due to the fact that the adopted telescope design can provide the amplification proportion of about 1: 1, fine adjustment of the conversion efficiency can be achieved.

Description

technical field [0001] The invention belongs to the field of pulse laser nonlinear conversion, in particular to a pulse laser frequency multiplier with continuously adjustable conversion efficiency and an adjustment method. Background technique [0002] Wavelength / frequency conversion of pulsed lasers using nonlinear crystals is a very common application requirement. In the process of conversion, conversion efficiency is a very important parameter, which is related to factors such as crystal thickness, conversion coefficient of material to incident light wavelength, and incident light power density. Too low conversion efficiency obviously has limitations. Common methods to increase conversion efficiency include increasing crystal thickness, increasing incident light power density, etc., but conversion efficiency is not necessarily as high as possible. For example, in the field of ultrafast lasers, in addition to the conversion efficiency, the time and space characteristics ...

AI Technical Summary

Problems solved by technology

Neither of these two methods can achieve continuous adjustment of conversion efficiency.

The ability to continuously adjust the spot size is very important for many applications. For example, in some scientific researches, the pulse width of the incident light needs to change continuously, while the frequency doubling conversion efficiency is required to remain unchanged. In this case, change the crystal thickness or use a fixed magnification The beam expansion / contraction of the telescope with magnification cannot meet the requirements

In order to solve the problem of continuously adjusting the conversion efficiency, some technical solutions also use a beam expander telescope composed of three lenses, which can adjust the beam expansion ratio within a certain range, but the lens layout adopted is concave, convex, and convex. Such a layout method can only expand the beam spot, or conversely use a convex, convex, and concave layout to shrink the beam spot. It is impossible to simultaneously expand and shrink the laser spot under the same layout. The big problem is that this scheme cannot fine-tune the size of the incident light spot, and for many applications, fine-tuning is required based on the current conversion efficiency, and this layout cannot meet such needs

Images