Economy Longpass Filters, 400-1100nm CWL
Longpass filters provide a wide blocking bandwidth, high blocking depth, high transmission and sharp slope. They are widely used in fluorescence excitation spectrum measurement, Raman spectrum, spectral group and astronomical observation applications. When combining with our shortpass filters, they can be used to set up variable bandwidth bandpass filters system. We also provide mounted filters which can be easily used in the optical system.
Note: Longpass filters are generally designed for 0° angle of incidence. Handling Instructions:
Always wear finger cots during handling; do not touch the filter surface directly with bare hands to avoid fingerprint contamination and optical performance degradation. If cleaning is required, wipe the surface gently with lint-free lens tissue dampened with alcohol. Do not use rough cloth or paper, or clean with pure water only, as this may damage the optical coating surface.
Parameters
| Material: H-K9L (CDGM) | TWE: λ/4@633 nm |
| Parallelism: < 30” | Surface Quality: 60/40 |
| Dia. tolerance: + 0.0/ -0.1 mm | Thickness: 2 ± 0.2 mm |
| Central wavelength(λC)*: ± 2% | Transmission: Tavg > 85% |
| Blocking depth: OD2 | Cutting Slope**: < 3% |
| Clear aperture: > 90% | AOI: 0° |
*Central wavelength(λC): The wavelength with transmission=50% T max
**Cutting Slope: (λ(T80%) -λ(T10%))/λ(T10%) *100%
Model
| Dia., mm | CWL, nm | Transmission band, nm | Blocking, nm |
| 12.5/25.0/50.0 | 400nm | 420~2000nm | 200~380nm |
| 450nm | 470~2000nm | 200~435nm | |
| 500nm | 520~2000nm | 200~485nm | |
| 550nm | 575~2000nm | 415~520nm | |
| 600nm | 625~2000nm | 460~575nm | |
| 650nm | 675~2000nm | 495~615nm | |
| 700nm | 725~2000nm | 535~665nm | |
| 750nm | 780~2000nm | 565~720nm | |
| 800nm | 830~2000nm | 600~765nm | |
| 850nm | 880~2000nm | 635~810nm | |
| 900nm | 935~2000nm | 675~860nm | |
| 950nm | 985~2000nm | 715~905nm | |
| 1000nm | 1035~2000nm | 750~955nm | |
| 1050nm | 1085~2000nm | 790~1005nm | |
| 1100nm | 1135~2000nm | 825~1050nm |