Meadowlark Optics
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Description
Data Sheet
Ordering Info
Resources
Description
Liquid Crystal Polarization Grating (LCPG) Technology
Non-mechanically reconfigurable optics with vastly superior size, weight, and power requirements compared to their mechanical counterparts.
DESCRIPTION
Meadowlark Optics’ Liquid Crystal Polarization Gratings utilize spatially varying birefringence to create highly efficient polarization-sensitive gratings. Circularly polarized light can be directed into either the +1 or -1 order depending on the handedness of the incident light. By using a stack of N LCPGs and half-waveplate switches, it is possible to steer to 2N discrete angles in 1-D or 2-D arrays.
Liquid crystal polarization gratings are also known as geometric phase gratings, Pancharatnam-Berry phase gratings, and diffractive waveplates. These transmissive gratings efficiently (> 99.5%) diffract circularly polarized light to either the first positive or negative order, based on the handedness of the incident light. By incorporating fast electro-optic half-wave polarization retarders to control the handedness of polarization, Meadowlark can develop custom LCPG devices and systems with a range of leading capabilities:
- Wide-angle beam steering > 100°
- Large apertures > 20 cm
- Sub-millisecond switching times
- Dramatically reduced size, weight, and power (SWaP) requirements
- Random-access and inertia-less beam steering
- Dynamic focusing also available
Non-Mechanical Steering for a Range of Aperture Sizes
Liquid crystal polarization gratings (LCPGs) are diffractive elements that provide near-100% diffraction for circularly polarized light. When layered with thin polarization-controlling liquid crystal elements, LCPGs provide a means of non-mechanically reconfiguring light into different states, such as for beam steering or focusing. Customers benefit from the patent on the pioneering work with LCPGs in non-mechanical beam steering (US 8,982,313 B2) as well as other related patents.LCPG Steering for Lidar
LCPG technology excels at non-mechanical beam steering for many narrowband sensors including lidar. To date, we have demonstrated LCPG beam steering for both coherent and direct detection lidars and both monostatic and bistatic architectures. Due to the ability to steer light in discrete steps over large angles, LCPG beam steering is particularly well suited to steering flash lidar systems and coherent doppler lidar wind sensing systems.Data Sheet
Download Data Sheet PDF
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Ordering Info
For specification, please contact Sales at 303.833.4333 or sales@meadowlark.com. Working with us personally ensures that you receive the exact component or system you need every time.
Resources
request a quote or get technical questions answered
DESCRIPTION
Meadowlark Optics specializes in precision polymer retarders for the visible to near-infrared region. Our Precision Retarders have the highest optical quality and tightest retardance tolerance of all polymer retarders. These true zero-order Precision Retarders consist of a birefringent polymer cemented between two precision polished, optically flat BK 7 windows. The retarder fast axis is conveniently marked for quick and easy reference. Precision Retarders are supplied with a broadband antireflection coating. Optical transmittance of a Precision Retarder is typically greater than 97%. The retardance δ at a wavelength λ that is different from the center wavelength λc is given by: δ ≈ δc(λc /λ) where δc is the retardance at λc.
This relationship is very important when using sources which vary in wavelength from their nominal value. The two graphs show the retardance behavior as a function of relative wavelength for a quarter and half‐wave retarder, respectively. The Mueller calculus can be used to calculate the transmitted polarization state based on the retardance differences from the ideal case.
Since polymer retarders are true zero‐order devices, they offer the significant advantage of improved angular performance. You can expect less than 1% retardance change over ±10°incidence angle.
Meadowlark Optics has developed precision ellipsometric techniques that can measure retardance to λ/1000. Our metrology for these measurements is the best in the industry. You can have absolute confidence that the calibration measurements supplied with your retarder are of the highest accuracy obtainable.
