Dichroic Filter Guide

Overview

Dichroic filters separate a broad spectrum of light into two components: a reflected component and a transmitted component. They provide the ability to select different bands from a spectrum and direct those bands to where they can either be used or discarded. Heat / UV control, color separation, and fluorescence microscopy are a few of the most common uses of dichroic filters.

Applications

Laser Beam Combining and Splitting

Dichroic laser beam combiners can efficiently combine or separate multiple laser beams at a 45° angle of incidence.

Description	Features
Dichroic Laser Beam Combiners	Combine or separate multiple laser beams Insensitive to polarization Ion-beam sputtered (IBS) coating Perfect for equipment with multi-laser sources	Dichroic Laser Beam Combiners
Ultrafast Laser Harmonic Beamsplitters	Separate or combine 400 nm & 800 nm Ti:Sapphire harmonics Minimum pulse dispersion Low wavefront distortion Hard refractory coatings for high damage threshold	Ultrafast Laser Harmonic Beamsplitters
High Energy Nd:YAG Laser Harmonic Beamsplitters	Separate or combine Nd:YAG harmonics and the 1064 nm primary High damage threshold Low wavefront distortion Hard refractory coatings for high damage threshold	High Energy Nd:YAG Laser Harmonic Beamsplitters

Longpass Filters

Dichroic Longpass Filters feature bands of very-low reflectance to create the transmission bands of the filters, and bands of very-high reflectance to create the blocking region of the filters.

Description	Features
Colored Glass Alternative Longpass Filters	Steep transitions from blocking to transmission Low autofluorescence High transmission of >90% average (typical) Excellent blocking of >5 OD	Colored Glass Alternative Longpass Filters
Square Colored Glass Alternative Longpass Filters	Steep transitions from blocking to transmission High transmission of >90% average (typical) Excellent blocking of >5 OD Patented Stabilife® coatings	Square Colored Glass Alternative Longpass Filters
Fluorescence Longpass Dichroic Filters	Patented Stabilife® Hard Coatings Lowest autofluorescence Maximum transmission Optimized optical fabrication for brilliant imaging	Fluorescence Longpass Dichroic Filters

Optical System Heat Control

Heat control dichroic filters are used to remove NIR heat from an optical system.

	Description	Features
	Heat-Reflecting Hot Mirrors	Remove unwanted heat from an optical system Reflect NIR heat & transmit VIS light at 0° 25.4 mm diameter or 50.8 mm square filters		Heat-Reflecting Hot Mirrors
	Heat-Transmitting Cold Mirrors	Remove unwanted heat from an optical system Reflect VIS light and transmit NIR heat at 45° 25.4 mm diameter or 50.8 mm square filters		Heat-Transmitting Cold Mirrors

UV Water Purification

254 nm dichroic filters can be used to accurately monitor the UV water purifying effectiveness of mercury lamps in real-time.

	Description	Features
	Mercury-SC 254 nm Shortpass Filters	≥80% transmission typical at 254 nm Qualified for up to 300° C high temperature Spectral stability in any environment Low autofluorescence		Mercury-SC 254 nm Shortpass Filters

Terahertz Visible Beamsplitting

The 2 in. Terahertz Visible Beamsplitter is designed to reflect terahertz wavelengths and transmit visible wavelengths.

	Description	Features
	Terahertz Visible Broadband Beamsplitters	ITO front surface optimized for 1-120 Thz AR coated back surface for visible wavelengths High quality N-BK7 substrates Beamsplitting ratio maintained over wide wavelength range		Terahertz Visible Broadband Beamsplitters