## Optical constants of CuGaS_{2} (Copper gallium sulfide)

Boyd et al. 1971: n(o) 0.55–11.5 µm; 20 °C

Wavelength:
µm

(0.55–11.5)

### Complex refractive index (*n+ik)*

n
k
LogX
LogY
eV

### Derived optical constants

### Dispersion formula

$$n^2-1=2.9064+\frac{2.3065λ^2}{λ^2-0.1149}+\frac{1.5479λ^2}{λ^2-738.43}$$### Comments

Ordinary ray (o); 20 °C

### References

1) G. D. Boyd, H. Kasper, J. H McFee. Linear and nonlinear optical properties of AgGaS_{2}, CuGaS_{2}, and CuInS_{2}, and theory of the wedge technique for the measurement of nonlinear coefficients, *IEEE J. Quant. Electron.*, **7**, 563-573 (1971)

2) G. C. Bhar and G. Ghosh. Temperature-dependent Sellmeier coefficients and coherence lengths for some chalcopyrite crystals, *J. Opt. Soc. Am.* **69**, 730-733 (1979)

*Ref. 2 provides a dispersion formula based on data from Ref. 1

### Data

## INFO

### Copper gallium sulfide, CuGaS_{2}

Copper gallium sulfide (CuGaS_{2}) is a ternary compound semiconductor that exhibits a chalcopyrite crystal structure. This material is notable for its non-linear optical properties and is frequently employed in non-linear frequency conversion applications such as second-harmonic generation and parametric down-conversion. Its large non-linear coefficients and extensive phase-matching capabilities make it an ideal choice for infrared and mid-infrared applications. The material also boasts high thermal conductivity and damage threshold, which lends itself well to high-power optical systems. While not as commonly used as some other non-linear optical materials, copper gallium sulfide remains a specialized choice for applications requiring efficient non-linear frequency conversion, particularly in the infrared spectrum.

#### Other name

- Copper gallium disulfide