BK7 Optical Glass Penta Prism
Featured Product from Changchun Yutai Optics Co., Ltd.
| Comparison between BK7 penta prism and fused silica penta prism | ||
| Properties | BK7 Penta Prism | Fused Silica Penta Prism |
| Transmission range | 350nm - 2.0μm | 185nm - 2.1μm |
| Ultraviolet performance | Poor (strong absorption below 350nm) | Excellent (high deep ultraviolet transmittance) |
| Thermal stability | Generally (with higher thermal expansion) | Excellent (low thermal expansion) |
| Laser damage threshold | Lower (5J/cm² @1064nm, 10ns) | High (10 J/cm²) |
| Cost | Lower | Higher |
| Applicable scene | Conventional applications of visible | Ultraviolet, high-power lasers, extreme environments |
FAQ about BK7 penta prism
Q1: Can BK7 penta prisms be used with UV lasers?
→ Not recommended. BK7 exhibits strong absorption in the <350nm wavelength. For UV applications, use a fused silica penta prism instead.
Q2: Is coating necessary?
→ If the angle of incidence exceeds the critical angle (about 41° for BK7), no coating is needed. Otherwise, a high-reflectivity (HR) coating is required.
Q3: Can it handle high-power lasers?
→ Suitable only for low-power lasers (<1 W CW). For high-power applications, consider fused silica prisms or those with laser-grade HR coatings.
