R16 645 nm longpass filter

R16 is a longpass filter. A high-transmission region is shown at approximately 649-780 nm.

Measured wavelength range: 380-780 nm
Edge at 50% transmission: ≈ 643.9 nm
Peak transmission: ≈ 95.7% at 767 nm
Transmission ≥80%: 649-780 nm
Transmission ≤5%: 395-631 nm
Custom options: Wavelength response, dimensions and operating conditions

Values shown are sample measurements. Final specifications are agreed for your order.

645 nm nominal-edge longpass filter (R16)

R16 is a longpass filter. A high-transmission region is shown at approximately 649-780 nm. Consider it when you need to pass longer wavelengths and reduce shorter-wavelength light within the measured range.

Optical performance

Measured wavelength range: 380-780 nm. Performance outside this measured interval is not established by this curve.
Selected regions at or above 80% transmission: 649-780 nm. Approximate measured intervals.
Selected regions at or below 5% transmission: 395-631 nm. Measured sample intervals; confirm the required blocking for your order.
Peak transmission: Approximately 95.7% at 767 nm. Peak wavelength is not the same as a defined centre wavelength.
Measured edge at 50% transmission: Approximately 643.9 nm. Interpolated absolute-transmission crossing, checked against the factory summary.
Customization: We can customize stock and sample-book designs. Tell us the wavelength response, size and operating conditions you need.

These values come from the measured samples and help you choose a starting design. We will agree the final specification for your order. Custom versions have their own specifications and measured curves.

Applications to consider

Illuminated machine vision: Consider a source operating inside 649-780 nm, with unwanted background on the shorter-wavelength side. Check the signal and background spectra together.
Broad spectral collection: Evaluate passing a range of longer wavelengths into a detector. Confirm its upper sensitivity limit because a longpass edge does not provide an upper band limit.
Fluorescence instrument development: Consider an emission-side longpass only when the excitation wavelength falls in a sufficiently attenuated region. Specify rejection at that exact wavelength and any additional blocking optics.

Choosing this filter

Check the full wavelength range of your light source, the wavelengths your detector responds to, and how much unwanted light you need to block. Use the full curve when choosing a filter; the product code and peak do not tell the whole story.
Tell us the angle at which light reaches the filter and whether the beam is parallel or converging. For demanding rejection or high-power use, confirm the required blocking and power-handling specifications.

Custom options

Start with this stock or sample-book design, then tell us what you need to change. We can discuss the wavelength bands, transmission, blocking, angle, glass material, size and operating conditions with you, and agree a specification for your custom filter.

Transmission spectrum

Questions about R16

Which part of the spectrum is most useful when choosing R16?

The measured regions at or above 80% transmission are 649-780 nm. They are measured intervals, not guaranteed passband tolerances. Compare the full curve with the signal wavelengths you need to retain.

Which low-transmission regions are shown for R16?

The measured regions at or below 5% transmission are 395-631 nm. That threshold is a way to summarize this sample, not a guaranteed blocking specification. For a weak signal beside a bright unwanted wavelength, tell us the actual wavelengths and maximum leakage you can accept.

Discuss this filter with KUPO - include the product reference, source wavelength, working angle and required dimensions.