Specification
While "BP1064-35" is a model number format used by various optical manufacturers (such as OptoSigma, MidOpt, or MOK Optics), the code itself decodes into specific optical parameters:
- BP: Bandpass Filter.
- 1064: Center Wavelength (CWL) of 1064 nm (Near-Infrared / NIR).
- 35: Full Width at Half Maximum (FWHM) of 35 nm. This means the filter passes light primarily between ~1046.5 nm and 1081.5 nm.
- T=90%: High transmission rate (>90%) within the passband, ensuring minimal signal loss.
- OD4 @ 200–1200nm: This indicates an Optical Density of 4 (blocking 99.99% of light) across the 200–1200 nm range, excluding the passband. This is a critical feature: it effectively "blinds" the sensor to all UV, Visible, and non-relevant IR light, allowing only the 1064 nm signal to pass.
Application - Active Night Vision & Surveillance
In security systems that use 1064 nm active illumination, this filter is placed over the camera lens. Since 1064 nm is invisible to the human eye (and shows no "red glow" like 850 nm LEDs), it allows for covert surveillance. The filter removes visible light, ensuring the image remains clear even if car headlights or streetlights are in the frame.
Recommended Light Sources
- High-Power 1064 nm IR Laser Illuminators (Primary Choice)
For active surveillance, laser-based illuminators are the standard choice at this wavelength.
Why they are used: Standard silicon camera sensors have low sensitivity at 1064 nm. To compensate, you need a light source with high intensity and long throw capabilities, which lasers provide much better than LEDs.
Key Advantage: They emit a coherent beam that can be shaped (narrow for long-range, wide for area monitoring) without the "red glow" associated with standard IR LEDs.
- High-Power 1064 nm LED Arrays
For shorter-range indoor or machine vision applications, specialized LED arrays are available.
Why they are used: They are generally safer (non-coherent light) and cheaper than laser illuminators.
Limitation: They have a broader spectral bandwidth. You must ensure the LED's output does not drift outside your filter's 35 nm passband (1046–1081 nm), or you will lose illumination power.