Liquid Crystal Polarization Grating Application Note
Meadowlark Optics Download the LCPG App Note Liquid Crystal Polarization
Key Features
Substrate Material: Corning EAGLE XG
Substrate Thickness: 0.02 in. (0.5 mm)
Transmitted Wavefront Distortion: ≤ λ/4 RMS at 532 nm (Typical)
Surface Quality: 60 – 40 scratch-dig
Item # | Size | Wavelength | Diffraction Efficiency | Total Efficiency | Clear Aperture | Diffraction Angle | Lead Time | Price | Quantity | Add to cart |
---|---|---|---|---|---|---|---|---|---|---|
PG-050-VIS-040 | 0.500 x 0.500 in. (12.70 x 12.70 mm) | 450 - 700 | ≥ 90% | ≥ 80% | 0.34 in. × 0.34 in. (8.7 mm × 8.7 mm) | ±4 | Please Inquire | $150.00 | Max: Min: 0 Step: 1 | |
PG-050-VIS-020 | 0.500 x 0.500 in. (12.70 x 12.70 mm) | 450 - 700 | ≥ 90% | ≥ 80% | 0.34 in. × 0.34 in. (8.7 mm × 8.7 mm) | ±2 | Please Inquire | $150.00 | Max: Min: 0 Step: 1 | |
PG-050-VIS-010 | 0.500 x 0.500 in. (12.70 x 12.70 mm) | 450 - 700 | ≥ 90% | ≥ 80% | 0.34 in. × 0.34 in. (8.7 mm × 8.7 mm) | ±1 | Please Inquire | $150.00 | Max: Min: 0 Step: 1 | |
PG-050-1550-100 | 0.500 x 0.500 in. (12.70 x 12.70 mm) | 1550 | ≥ 99% | ≥ 90% | 0.34 in. × 0.34 in. (8.7 mm × 8.7 mm) | ±10 | Please Inquire | $150.00 | Max: Min: 0 Step: 1 | |
PG-050-1550-050 | 0.500 x 0.500 in. (12.70 x 12.70 mm) | 1550 | ≥ 99% | ≥ 90% | 0.34 in. × 0.34 in. (8.7 mm × 8.7 mm) | ±5 | Please Inquire | $150.00 | Max: Min: 0 Step: 1 | |
PG-050-1550-025 | 0.500 x 0.500 in. (12.70 x 12.70 mm) | 1550 | ≥ 99% | ≥ 90% | 0.34 in. × 0.34 in. (8.7 mm × 8.7 mm) | ±2.5 | Please Inquire | $150.00 | Max: Min: 0 Step: 1 | |
PG-050-1550-010 | 0.500 x 0.500 in. (12.70 x 12.70 mm) | 1550 | ≥ 99% | ≥ 90% | 0.34 in. × 0.34 in. (8.7 mm × 8.7 mm) | ±1 | Please Inquire | $150.00 | Max: Min: 0 Step: 1 | |
PG-050-1064-050 | 0.500 x 0.500 in. (12.70 x 12.70 mm) | 1064 | ≥ 99% | ≥ 90% | 0.34 in. × 0.34 in. (8.7 mm × 8.7 mm) | ±5 | Please Inquire | $150.00 | Max: Min: 0 Step: 1 | |
PG-050-1064-025 | 0.500 x 0.500 in. (12.70 x 12.70 mm) | 1064 | ≥ 99% | ≥ 90% | 0.34 in. × 0.34 in. (8.7 mm × 8.7 mm) | ±2.5 | Please Inquire | $150.00 | Max: Min: 0 Step: 1 | |
PG-050-1064-010 | 0.500 x 0.500 in. (12.70 x 12.70 mm) | 1064 | ≥ 99% | ≥ 90% | 0.34 in. × 0.34 in. (8.7 mm × 8.7 mm) | ±1 | Please Inquire | $150.00 | Max: Min: 0 Step: 1 |
Meadowlark Optics’ Liquid Crystal Polarization Gratings utilize spatially varying birefringence to create highly efficient polarization-sensitive gratings. Liquid crystal polarization gratings are also known as geometric phase gratings, Pancharatnam-Berry phase gratings, and diffractive waveplates.
At the wavelength(s), where the birefringent layer provides a half wave of retardation, these transmissive gratings efficiently (> 99.5 % typical) diffract circularly polarized light to either the + 1 or – 1 order depending on the handedness of the incident light. Because of the half wave of retardation, the diffracted light also changes handedness relative to the incident light. Meanwhile, when linearly polarized light is used, the light is evenly split into the two diffracted orders. Meadowlark Optics offers a commercial product line of LCPGs at common laser wavelengths and a variety of diffraction angles. Broadband visible LCPG options are also available.
The plots under the “Graphs/Figures” tab illustrate the typical diffraction spectra of narrowband (left) and broadband (right) LCPGs by measuring the leakage into the 0th order (i.e., undiffracted transmission). Peak diffraction efficiency occurs where the plots have a null, representing > 99.5 % diffraction efficiency in both cases.
NARROWBAND LCPG SPECIFICATIONS | |
Design Wavelengths | 532 nm, 1064 nm, 1550 nm (please specify) |
Diffraction Angles | 532 nm: ± 1˚, ± 2˚, ± 4˚ 1064 nm: : ± 1˚, ± 2 .5˚, ± 5˚ 1550nm: ± 1˚, ± 2.5˚, ± 5˚, ± 10˚ |
Diffraction Efficiency† | ≥ 99% |
Total Efficiency‡ | ≥ 90% |
BROADBAND VISIBLE LCPG SPECIFICATIONS | |
Wavelength Bandwidth | 450 – 700 nm |
Diffraction Angles at 532 nm / (Grating Pitches) | ± 1˚, ± 2˚, ± 4˚ / (30.5 µm, 15.2 µm, 7.6 µm) |
Diffraction Efficiency† | ≥ 90 % over 450 nm – 700 nm ≥ 95 % over 550 nm – 650 nm |
Total Efficiency‡ | ≥ 80 % over 450 nm – 700 nm ≥ 85 % over 550 nm – 650 nm |
SHARED SPECIFICATIONS | ||
Substrate Material | Corning EAGLE XG | |
Substrate Sizes / Clear Apertures | 0.5 in. × 0.5 in. (12.7 mm × 12.7 mm) 1.0 in. × 1.0 in. (25.4 mm × 25.4 mm) | 0.34 in. × 0.34 in. (8.7 mm × 8.7 mm) 0.76 in. × 0.76 in. (19.4 mm × 19.4 mm) |
Substrate Thickness | 0.02 in. (0.5 mm) | |
Transmitted Wavefront Distortion | ≤ λ/4 RMS at 532 nm (Typical) | |
Surface Quality | 60 – 40 scratch-dig |
†Diffraction Efficiency defined as the power in the desired first-order beam divided by the sum of all power in all diffracted orders. Assumes circularly polarized incident light.
‡Total Efficiency defined as the power in the desired first-order beam divided by the power in the incident beam. Includes surface reflection losses.
Our commercial product line consists of unmounted LCPGs without integrated anti-reflection (AR) coatings so that we can provide customers with the best price. Please contact our knowledgeable Solutions Engineers regarding custom options, including custom diffraction angles, aperture sizes, and wavelengths through the visible to midwave infrared.
Fundamentals
Liquid crystal polarization gratings (PGs) are fascinating optical components that differ from traditional diffraction gratings, like ruled, Bragg, or holographic gratings. In particular, PGs exhibit polarization sensitivity, can have diffraction efficiency approaching 100%, and are much less sensitive to incident angle than, for example, Bragg or volume holographic gratings. To understand how this is possible, it is important to first understand how PGs work.
These plots show typical zero-order leakage spectra for different LCPG specifications. The LCPG diffraction efficiency is highest where the zero-order leakage is at a minimum.
Meadowlark Optics Download the LCPG App Note Liquid Crystal Polarization
Download PDF Fundamentals Liquid crystal polarization gratings (PGs) are fascinating
Geometric-phase microscopy (GPM) uses changes in the phase of light