<title>Gained experience in production of wide-aperture optical elements using KDP, DKDP crystal rapid growth technology</title>

Abstract

Optical elements made of KDP, DKDP crystals (Pockels elements, frequency conversion elements, phaseplates) are up to now among the most expensive and significant ones in high-power laser systems with frequency conversion into higher harmonics. Only some companies have mastered such production technology of optical elements with the aperture size up to 40x40 cm. The production is characterized by very long cycles of crystal growth and large waste at manufacturing opticai elements, which leads to an extremely high price ofthe products. An alternative technology based on rapid technology of profiled growth of crystal products and the technology of optical diamond micromilling by means of ISM-600 machines are developed now at the Institute of Applied Physics RAS. The cycle duration of the crystal product growth reduces tens times, cuffing of the grown product mto optical elements proves to be practically wasteless This leads to reduction ofproduct cost and significant shortenmg ofproduct cycle duration The quality of crystal growth and optical processing is consistent with the requirements of optical systems. This together with the described applied technologies has permitted to manufacture optical elements for a series ofhighpower lasers.

Rotary ultrasonic machining of potassium dihydrogen phosphate (KDP) crystal: An experimental investigation on surface roughness

“…Because of its unique properties, potassium dihydrogen phosphate (KDP) crystal can be widely used for parts of sonar and piezoelectric products [1], Q-switches [2], high speed photography shutters [2], electro-optical modulators [3], and frequency harmonic generation lens [4][5][6][7][8][9][10][11].…”

Light Scattering in KDP Crystals and Relaxation Oscillations of Diffusion Layer in Crystal Growth from Solutions

“…A model corresponding to the high-rate profiled growth technology [1,2] is chosen as the basic model of crystal growth. The schematic of the setup for growing crystals by a single face fed by a supersaturated solution through a periodically moving feeder [1,2] is shown in Fig. (1), and the scheme of the solution flow directed to the crystal face in this setup is presented in Fig.…”

“…High optical quality of crystals (specifically of KDP monocrystals) grown from solution is still an important problem. It is closely connected with the development of new efficient techniques [1][2][3] of crystal growth and increased demands to the quality of crystals to be used, for example, in high-power lasers [4][5][6]. The main quality indexes, such as optical transparency, optical homogeneity, and laser breakdown threshold are related to growth perfection.…”

“…However, crystal growth in real conditions is much more complicated: the solution flow velocity and the diffusion layer thickness are nonuniform over the growing surface and vary in time. In the high-rate profiled growth technology [1,2], the solution is fed onto the growing surface through a feeder periodically moving along the surface, whereas in the high-rate polyhedral technology [3], the crystal rotates reversibly, following a special program. Besides, a crystal usually does not grow by a single growth center and, in the technology described in [3], by a single face.…”

An experimental investigation on slicing of potassium dihydrogen phosphate crystal

“…Because of its unique properties, potassium dihydrogen phosphate (KDP) crystals are widely used for electrooptical applications. [1][2][3] For example, large KDP crystal parts (with a size of 410 mm 3 410 mm 3 10 mm) are used as optical harmonic generation lens and Pockels electro-optical switches for the application of inertial confinement fusion. 4,5 Table 1 lists some mechanical properties of KDP in comparison with three commonly used materials (tool steel, alumina, and silicon carbide).…”