Model and experimental investigation of frequency conversion in AgGaGe_xS_{2(1 +x)}(x= 0, 1) crystals

Abstract

Analysis of available and developed data on phase matching in AgGaGe x S 2(1+x) (x = 0, 1) crystals is carried out. Nanosecond AgGaS 2 type I optical parametric oscillator with a continuously tunable range 2.65-5.29 µm is demonstrated pumped by a Q-switched Nd : YAG laser. An output pulse energy of up to 0.56 mJ at 4 µm is recorded. Phase matching of second harmonic generation in both crystals is represented. Best sets of Sellmeier equations for two crystals are determined.

Synthesis and growth of nonlinear infrared crystal material AgGeGaS4 via a new reaction route

“…Many crystals such as AgGaSiSe 4 , CuGaSnSe 4 , AgGeGaS 4 , and AgAlGeSe 4 have been studied [2][3][4]. Due to various reasons, some of them could not grow into single crystals, but the others, especially, AgGeGaS 4 (AGGS) crystal has been paid much attention because of its unique structure, special properties, including the capability of using as nonlinear optical element in second harmonic generation (SHG), difference frequency generation (DFG) and optical parametric amplification (OPA) [5][6][7][8]. Also, AGGS is the most promising material for parametric light generators in mid-far IR range with Nd:YAG laser radiation pumping due to the weak absorption around 1 mm, high radiative resistance (230 MW/cm 2 ), and large birefractive index [5].…”

LiInSe 2 nanosecond optical parametric oscillator tunable from 4.7 to 8.7 µm

“…*related data can be found in Ref 28. 29 but the results in terms of output energy and tuning range do not represent an improvement in comparison with Ref 9…”

Hybrid iterative learning fault‐tolerant guaranteed cost control design for multi‐phase batch processes

“…Moreover, the performance index values of the corresponding closed-loop system satisfy the inequality (27).…”

“…Nowadays, how to suppress the disturbance in the system and the effect of the actuator failure on the system control has become a hot topic among experts and scholars. [27][28][29][30] In order to solve this problem, a multi-phase batch process with faults and disturbances is considered and hybrid iterative learning fault-tolerant guaranteed cost control scheme is proposed. The faulty system is first treated into an equivalent 2D-FM switched system model with different dimensions.…”

“…[27] Let D, F, E, and M denote real matrices with appropriate dimensions and M satisfy M ¼ M T , then for all F T F I:M þ DFE þ E T F T D T < 0if and only if there exist e > 0 such that:…”