# Arsenic trisulfide, As2S3

As2S3, also known as arsenic trisulfide, exists in both crystalline and amorphous forms. The crystalline form is commonly referred to as orpiment and occurs naturally as a mineral. However, in optical and photonic applications, the amorphous or glassy form of As2S3 is often preferred. This chalcogenide glass features a broad transmission window that extends from the visible to the mid-infrared spectral regions, and it is known for its high nonlinear optical coefficients. The amorphous structure allows for the material to be easily molded, drawn into fibers, or deposited as thin films, making it highly versatile for a variety of optoelectronic applications. It also offers the advantage of strong light confinement due to its high refractive index. However, users should exercise caution as the material contains toxic arsenic, and its photosensitive nature necessitates consideration for stability under light exposure. Whether in its crystalline or amorphous state, As2S3 remains a material of significant interest for both its unique optical properties and its potential in emerging technologies.

## Other names

- Arsenic(III) sulfide
- Diarsenic trisulfide
- Arsenic trisulphide
- Arsenic(III) sulphide
- Diarsenic trisulphide

## Mineral

- Orpiment

## External links

- Arsenic trisulfide - Wikipedia
- Diarsenic trisulphide - WebElements