Cold mirrors and hot mirrors are two types of specialized dichroic mirrors. They operate not by temperature but by optical properties to separate light energy, functioning as remarkable components for spectral management using the principle of precise optical interference filters. A cold mirror is designed to highly reflect visible light while transmitting infrared radiation. In contrast, a hot mirror performs the opposite function: it highly reflects infrared light while transmitting visible light.
Cold mirror (spectral cooling) | hot mirror (heat blocking)
Cold mirror: Short-pass interference filter | hot mirror: Long-pass interference filter
High precision & efficiency
| Material | Borofloat |
| Surface Flatness | ＜5λ/25mm²@633nm |
| Parallelism | < 3 arcmin |
| Diameter Tolerance | ±0.2mm |
| Thickness Tolerance | ±0.2mm |
| Surface Quality | 60/40-80/50 |
