A dichroic has selective absorption of one polarisation state, transmitting the other. Available in lower cost polymers and higher precision glass. Suitable for lower power (~W’s), larger aperture applications
Polymer
DP, DPM Polarisers are precision linear polarisers using dichroic polymer sheet polariser material laminated between high quality glass substrates. For visible wavelength polarisers, this construction produces a peak-to-valley transmitted wavefront distortion of less than λ/5. Various polariser materials are used to cover wavelengths within 320 and 2000 nm. Both visible and near infrared polarisers are supplied with a high-efficiency, broadband antireflection (AR) coating; single-layer AR coatings are optional on our ultraviolet polarisers.
The GPM series is extremely broadband (300-2700nm) with up to 1,000,000:1 contrast ratio, rivalling the span of Glan-Thompson polarisers but in a compact design. Wide acceptance angle (±40°) and large clear aperture
Dichroic Glass
PPM, UPM and UHP based on Dichroic Glass. The PPM is in response to improved contrast in the NIR region, contrast ratio’s as high as 10,000:1,
Custom wavelength ranges from 630 to 1580 nm with 60 to 80nm bandpasses and sizes from 10 to 25 mm are available.
The UPM and UHP are ultra- high contrast (>100,000:1) polarisers the UPM being mounted on the UHP being unmounted, both can be laminated or unlaminated with unlaminated parts usable to 400°C. AR coating options available from 400-1700nm.
Dichroic Circular
CP, CPM Circular polarisers transmit either left‐circular polarised light or right‐circular polarised light for an input beam of any polarization state. When circularly polarised light is reflected, it’s propagation direction reverses, changing left‐circular polarisation to right circular polarisation and vice‐versa
Meadowlark Optics Dichroic Circular Polarisers consist of a dichroic linear polariser and true zero-order quarter-wave retarder. Precisely aligning the retarder fast axis at 45° to the linear polarisation direction ensures optimum performance.