The first is excitation cleanup: a light source that should emit only its design band often leaks longer-wavelength light, and a shortpass in front of it trims the leak before it reaches the sample. The second is rejection at the detector: silicon sensors respond well into the infrared, and a shortpass keeps that infrared response from contaminating a visible-band measurement — the same reason shortpass behaviour is built into the IR-cut filters used on cameras, covered on the IR cut filters page.
The manufacturer's documented filter group lists shortwave-pass filters as a family of their own, alongside long-pass, bandpass, narrowband, infrared and notch filters. That family position matters for specification: the fields a shortpass enquiry asks for first are its cut-off edge and its blocking depth in the infrared, and the natural quotation conversation covers the edge wavelength, the passband range below it, substrate size and the angle of use.
Specifying a Shortpass Filter
- Cut-off wavelength — where the edge falls between the passband and the blocked infrared.
- Passband range — how far into the ultraviolet or blue the transmission must hold.
- Blocking band — the infrared range to be rejected, and how deep the rejection must be.
- Angle of incidence — not recorded for the group; state the angle of use in the enquiry.
Shortpass and longpass filters are most powerful as a pair: crossed edges from the two families carve out a band with steeper sides than either alone. If your requirement is actually a defined band rather than a single edge, the bandpass page is the direct route. Minimums and pricing for shortpass filters are confirmed per specification in the written quotation.
Frequently Asked Questions
Shortpass or IR cut — are they the same thing?
Related but not identical: an IR cut filter is a separate listing in the filter catalogue, documented under that listing name; the fields a shortpass enquiry asks for first are its cut-off edge and its blocking depth in the infrared.
Can a shortpass block heat radiation?
Yes — rejecting the infrared beyond the edge is one of the functions a shortpass element performs.
What should my enquiry include?
Cut-off wavelength, passband range, blocking range, size and quantity.
Shortpass Filters in Heat and Light Control
A less obvious shortpass duty deserves a paragraph because it drives real orders: heat control in illumination. Sources that deliver visible light also deliver infrared, and in microscopy, machine vision and projection that infrared is pure cost — it heats the sample, the optics and the sensor without adding image. A shortpass element in the illumination path, passing the visible band and rejecting the infrared beyond its edge, is the standard cure, and its specification is a system one: the edge must sit above the longest wavelength the imaging needs and below the infrared the source pours out, and the element must handle the absorbed or reflected energy at the source's full power. State the source type and power in the enquiry. Combined with the detector-side use described above, both ends of the job can fall inside a single instrument — one shortpass-class element cleaning the light going in, one cleaning the light being seen.
Request a Quotation
Tell us the component, material, dimensions and coating you need. Pricing and lead time for your specification are confirmed in the written quotation.