Interference band-pass filters These Interference Band pass Filters are used to isolate and transmit a narrow wavelength that is required and block all other wavelengths through reflection. This range of Interference Band pass Filters consist of an all-dielectric coating along with other coatings for additional blocking and cemented together to form a stack. The individual filters are mounted in nested rings, providing a labyrinth epoxy edge seal for greatly extended life. Although these are mounted, unmounted type can be supplied at special request. These Interference Band pass Filters are all typically 3-7 cavity. Uses include line selection, laser signal selection, colorimetry and fluorimetry. They can also be used for imaging. When using high powers the reflective side must be towards the incoming light.
Knight Optical > Filters > Interference band-pass filters > Standard range (10nm bandwidth) > 12.5 diameter (mm) Only UK and EU customers are charged VAT at 17.5%, customers outside the EU and EU customers based outside the UK who have a valid EU VAT number will not be charged VAT Bulk Discounts! Where (B) appears next to a price below, bulk prices are available, click the (B) button to view! PDF Part No. Wavelength (CWL nm) Bandwidth (HBW nm) Peak transmission (%) Price Qty Buy 254FIB12 254.7 8 17 £148.00 288FIB12 288 8 17 £97.80 330FIB12 330 10 25 £43.00 337FIB12 337.1 10 25 £43.00 340FIB12 340 10 25 £37.00 350FIB12 350 10 30 £43.00 355FIB12 355 10 30 £43.00 360FIB12 360 10 35 £43.00 365FIB12 365 10 35 £37.00 370FIB12 370 10 35 £43.00 380FIB12 380 10 45 £21.00 390FIB12 390 10 45 £21.00 400FIB12 400 10 45 £18.50 405FIB12 405 10 45 £18.50 410FIB12 410 10 45 £18.50 415FIB12 415 10 45 £24.25 420FIB12 420 10 45 £18.50 430FIB12 430 10 45 £18.50 436FIB12 435.8 10 45 £18.50 440FIB12 440 10 45 £18.50 450FIB12 450 10 45 £18.50 458FIB12 457.9 10 45 £17.50 460FIB12 460 10 45 £17.50 470FIB12 470 10 45 £17.50 480FIB12 480 10 45 £17.50 488FIB12 488 10 45 £17.50 490FIB12 490 10 45 £17.50 500FIB12 500 10 50 £17.50 510FIB12 510 10 50 £17.50 515FIB12 514.5 10 50 £17.50 520FIB12 520 10 50 £17.50 530FIB12 530 10 50 £17.50 532FIB12 532 10 50 £17.50 540FIB12 540 10 50 £17.50 543FIB12 543 10 50 £17.50 546FIB12 546.1 10 50 £17.50 550FIB12 550 10 50 £17.50 560FIB12 560 10 50 £17.50 570FIB12 570 10 50 £17.50 578FIB12 577.7 10 50 £17.50 580FIB12 580 10 50 £17.50 589FIB12 589.6 10 50 £17.50 590FIB12 590 10 50 £17.50 600FIB12 600 10 50 £17.50 610FIB12 610 10 50 £17.50 620FIB12 620 10 50 £17.50 630FIB12 630 10 50 £17.50 633FIB12 632.8 10 50 £17.50 633FIJ12 632.8 10 75 £25.00 636FIB12 636 10 50 £17.50 640FIB12 640 10 50 £17.50 645FIB12 645 10 50 £17.50 650FIB12 650 10 50 £17.50 656FIB12 656.3 10 50 £17.50 660FIB12 660 10 50 £17.50 670FIB12 670 10 50 £17.50 680FIB12 680 10 50 £17.50 690FIB12 690 10 50 £17.50 694FIB12 694.3 10 50 £17.50 700FIB12 700 10 50 £17.50 710FIB12 710 10 50 £17.50 Knight Optical > Filters > Interference band-pass filters > Standard range (10nm bandwidth) > 12.5 diameter (mm)
Dimensions   Diameter: +0,-0.3mm Thickness: 5-6mm Clear aperture:   12.5mm dia. 8.6mm 25mm dia. 19mm 50mm dia. 44mm   Specification
Range Fin FIB (<1100nm) FIB (=1100nm) FIJ FIR FIW CWL tolerance (nm) +0.7,-0.4 ±2 ±3 ±2 ±5 ±7 HBW tolerance (nm) +0.7 ±2 ±3 ±2 ±5 ±8 Bandwidth ratios*             10%BW/HBW 1.74 1.35 1.74 1.35 1.13 1.05 1%BW/HBW 3.21 1.99 3.21 1.99 1.30 1.18 0.1%BW/HBW 6.09 2.92 6.09 2.92 1.60 1.36 0.01%BW/HBW 12.68 4.41 12.68 4.41 2.04 1.69 Blocking type and specification Induced transmittance filter10?? absolute, 200-3500+ Dielectric stacks:10?? ave,10?³ abs, x-ray to 1150nm No of cavities (min) 2 3 2 3 5 7
Interference filter glossary Bandwidth (HBW, FWHM): Width of the passband; specifically, the difference between the two wavelengths at which the transmittance is half the peak value. Similarly, 10% bandwidth (10%BW) is measured between points where T=10% of peak, etc. Blocking: Rejection of any energy outside the passband. Absolute blocking is the transmittance level not exceeded at any point in the specified wavelength range. Average blocking is a value averaged over a range. Cavity: The basic element from which a filter is constructed, consisting of two reflective coating stacks with a spacer layer in between. Our standard range is based on a series of three cavities and therefore a squarer shape of passband. Centre wavelength (CWL): The wavelength midway between the half-power points which define bandwidth (se above) Transmittance (T): The guaranteed minimum value of peak transmittance of the filter (not necessarily occurring at the centre wavelength) Technical Notes To estimate the transmittance near the passband, use the bandwidth ratios given in "specifications" e.g. 340FIB12 has HBW-10; for FIB range 1%BW/HBW=1.99,so 1%BW-19.9; .e transmittance ill be 1% of pea (about 0.3% absolute) at 340nm ±(19.9/2), i.e. about 30nm and 350nm. For light incident at an angle the centre wavelength ?o (1-k sin²?) where k is approximately 0.24 for FIW filters and 0.11 for all others. The CWL shifts towards the longer wavelengths with increasing temperature at about 0.1nm/K.