Transmits wavelengths longer than the cut-on while effectively blocking shorter wavelengths. Offering high transmission and deep blocking (OD), they are ideal for Raman spectroscopy and spectral order sorting.
Diameter range: 5 mm- 200 mm ±0.1 mm
Dimensional tolerance: ±0.05mm
Center wavelength: 350nm-2500nm
Surface Accuracy: λ/8
A longpass filter is designed to selectively transmit longer wavelengths within a specified spectral range while blocking (cutting off) shorter wavelengths, thereby effectively isolating and eliminating short-wave radiation while allowing long-wave radiation to pass through.
| Material | K9, Bk7, GJS1, GJS2,GJS3, B270 |
| Diameter tolerance | ±0.05 mm |
| Surface accuracy | λ/4@ 633nm or λ/10@633nm |
| Surface quality (S/D) | 60/40 or 20/10 |
| Effective caliber | 90% |
| Chamfer/beve | <0.1*45° |
| Center wavelength | 350nm-2500nm |
| Peak transmittance | >90% customized upon request |
| Half-peak bandwidth | 10nm-15nm |
