BBP-850D Bandpass Filter
BBP-850D isolates the 850 nm channel with ~92–95 % peak transmission and near-baseline leakage across VIS–NIR—ideal for biometrics, tracking, and NIR machine vision.
- Peak transmission: ~92–95 % T @ 840 – 870 nm
- Band edges: Steep cut-on/cut-off around the 850 nm region
- Out-of-band (VIS–NIR): ~0–1 % T across ~300 – 1100 nm
- SWIR window: ~60–65 % T @ 1180 – 1210 nm (optional extra blocking)
- Ghost control: Optional rear AR and slight wedge available
- Substrates: Borofloat®, Eagle XG, D263 T (≤ 450 °C), soda-lime (≤ 150 °C)
- Size / thickness: 5 – 450 mm • 0.21 – 3.8 mm (custom cut & dicing)
Learn more
BBP-850D is a narrow near-infrared bandpass centred around 850 nm, delivering
~92–95 % peak transmission in the ~840–870 nm window with steep edges that rapidly suppress
out-of-band light. Outside the main passband, transmission stays near baseline (~0–1 %) across
most of 300–1100 nm to reduce background and improve signal-to-noise under mixed illumination.
Note for SWIR-sensitive detectors: a secondary window can appear near ~1180–1210 nm and reach
~60–65 % transmission. If your sensor responds beyond 1.1 µm, KUPO can add an additional
blocking stack to fully suppress that band.
Typical uses: 850 nm IR illumination, biometrics/access control, IR beacons & tracking,
reflectance/absorption photometry, and industrial inspection where the 850 nm band must remain clean.
KUPO supplies rear-surface AR, slight wedge, and rapid custom cutting—from small test chips to 450 mm
plates—on high-temperature glass (Borofloat®, Eagle XG, D263 T) or economical soda-lime.
Description
The BBP-850D is an ultra-narrow near-infrared filter centered at 853 nm with an extremely tight 18 nm FWHM passband (843-861 nm). Peak transmission reaches 93.7 %. This is the narrowest of all 850 nm variants, sacrificing some light collection for exceptional spectral purity. Deep blocking everywhere (< 10 % across visible and most NIR) makes BBP-850D ideal for applications requiring monochromatic 850 nm isolation or when spectral crosstalk must be eliminated.
Key Advantages
- Monochromatic 850 nm isolation – 18 nm FWHM - tightest of all 850 variants for pure wavelength selection and zero spectral crosstalk
- Exceptional blocking depth – < 10 % transmission across visible, 700-850 nm, and 850-1000 nm regions for clean 850 nm only
- Hard-oxide ion-assisted coating – Dichroic multilayer ensures stable performance across thermal extremes and environmental stress
- Flexible format options – Custom round, square, and free-form blanks from 5 mm to 450 mm with thickness 0.21-3.8 mm
- Diverse substrate grades – Borofloat, soda-lime, Schott D263 T, and Corning Eagle XG support your optical architecture
Typical Applications
- Monochromatic laser filtering – Pure 850 nm laser line isolation for metrology and precision measurement systems
- Spectroscopic analysis – Ultra-narrow-band photometry in research and analytical chemistry
- Scientific instrumentation – Precision wavelength selection in optical research and laboratory instruments
- Fiber-based systems – Wavelength-selective filtering in telecommunications and fiber optic sensor networks
- Specialized sensing – Applications requiring absolute spectral purity and elimination of wavelength crosstalk
Implement BBP-850D for monochromatic 850 nm applications with rapid custom prototyping. We support both laboratory development and production deployment.
FAQ
BBP-850D FAQ
What is BBP-850D and what is it used for?
BBP-850D is a Ultra-narrow 850 nm bandpass for maximum spectral selectivity. The BBP-850D is an ultra-narrow near-infrared filter centered at 853 nm with an extremely tight 18 nm FWHM passband (843-861 nm). Peak transmission reaches 93.7 %. Common uses include Monochromatic laser filtering, Spectroscopic analysis, Scientific instrumentation, and Fiber-based systems.
What are the key optical specs of BBP-850D?
Key published specs for BBP-850D include Centre wavelength (CWL): 851.9 nm; Bandwidth (FWHM): 18.2 nm; Peak transmittance: ≥ 93.7 % T; Passband range: 842 – 861 nm; Edge steepness: ~8 nm (10 → 90 % per edge).
What applications is BBP-850D best suited for?
BBP-850D is commonly used for Monochromatic laser filtering, Spectroscopic analysis, Scientific instrumentation, and Fiber-based systems. Monochromatic laser filtering - Pure 850 nm laser line isolation for metrology and precision measurement systems.
Can BBP-850D be customized for size, substrate, or coating requirements?
KUPO lists the construction for BBP-850D as Ion-assisted hard-oxide; 5 – 450 mm shapes, 0.21 – 3.8 mm thick. Published custom options include CWL shifting, bandwidth tuning, custom blocking ranges, rapid prototypes. Flexible format options - Custom round, square, and free-form blanks from 5 mm to 450 mm with thickness 0.21-3.8 mm.
What should I know about angle of incidence and durability for BBP-850D?
The published angle of incidence for BBP-850D is 0° (normal incidence); custom angles available. The hard-oxide coating is built for repeated handling, heat, and cleaning.
