As optical components become integrated into OEM devices there is a need to restrict the dimensions of these components to ensure total package size requirements can be met. More importantly the parts must be manufactured without any loss in quality or optical characteristics. Meadowlark Optics has developed processes that allow us to efficiently build small polarizers and retarders, down to a few millimeters on a side for square parts or as tiny as 6 mm in diameter. Amazingly, these advancements are not only restricted to static components. Our active liquid crystal devices have gone even smaller than static parts, including some devices with a 1 mm circular clear aperture inside of a 3mm square device.
When designing an optical instrument there are often difficult challenges that force optics to be installed in tight spaces to even tighter tolerances. Custom mounts are often required to hold components of varying sizes and shapes that cannot be supported by traditional mounting options. Sub-assemblies often require polarization components be mounted with sub degree accuracy, or be tilted to very specific angles away from normal incidence.

Many applications require that researchers and scientists visualize minute concentrations of elements or compounds, or the changes in a continuous wavelength range. Meadowlark Optics line of Tunable Optical Filters allows the user to dissect an image into hundreds of individual wavelength images. Solar astronomers have used LC Tunable Filters for years (examples: imaging of solar flares and prominences or imaging the solar chromosphere) and now new applications in microscopy, spectroscopy, hyperspectral imaging and many other fields are being discovered and tested every day.

Design and construction of Tunable Optical Filters combines multiple areas of Meadowlark Optics expertise, including our Liquid Crystal Variable Retarders, instrumentation, fabrication and of course polarization. Our knowledge has led to designs that overcome many issues that have been overlooked in the past. For example, the retardance of a LC cell is sensitive to temperature and variations in the environment surrounding the device can lead to measurement errors. As a result we have mounted our Tunable Optical Filter inside a thermally controlled housing to preserve the tuning accuracy of the device.

If the specifications of our standard devices are not ideal for your application we are very interested in designing a custom Tunable Filter to exactly meet your needs. Choose the wavelength range, full width at half maximum (FWHM) of the transmission peaks, tuning resolution, angular field-of-view and a number of other requirements and Meadowlark Optics will design the system needed to complete your experiments. We even have designs that allow for a variable FWHM at a single wavelength! Please refer to the Tunable Optical Filter section of the catalog for more detail on these systems or call us to discuss your application requirements.

The applications for Spatial Light Modulators (SLMs) are broad and far reaching. From ultrafast laser pulse shaping to wavefront correction many tasks can be completed with our standard Linear and two-dimensional Hexagonal arrays. However, certain applications require larger active areas (clear apertures) in order to modulate the entire beam profile or maybe the pixels need to be arranged in a custom layout, like a series of concentric circles, for the experiment to be completed properly. Meadowlark Optics would like to take on your need for a custom designed transmissive SLM. Modifications to the pixel size, dimensions and pattern can be completed by creating a new photo-mask and since the optical head, driver and software can be kept the same these changes can be completed without dramatic price increases or lead-times.

In an effort to offer more versatile products Meadowlark Optics has designed extremely broadband (650 to 2000 nm) polarizing beamcube based around our line of VersaLight wire grid polarizers. Laminating a Versa- Light polarizer inside two right angle prisms allows the component to exhibit the benefits of both the polarizer and cube. This means that you have an extremely broadband cube with a large acceptance angle that is easy to mount. These cubes can be made to transmit any polarization direction while reflecting the orthogonal polarization.

Most broadband polarizing beamcubes offer a useable wavelength range of 300-400 nm. The VersaLight beamcube offers a useable range of 1350 nm and can be used from 650-2000 nm without much variation in transmission or loss of contrast ratio. In fact, this cube has a transmitted contrast ratio of 500:1 or better through most of the useable wavelength range. It also pushes the limits of the field of view for polarizing beamcubes. The angular acceptance of the VersaLight cube is greater than ± 20°, compared to ± 3° for most thin film beamcubes, opening up many uses and applications that were not possible with thin film polarizer designs. This cube continues the Meadowlark Optics tradition of innovation and quality construction by providing better specs and more performance to our customers, allowing them to do and see things that were never possible before.

When completing an application where the wavelength of interest is different from a standard light source wavelength it can be difficult to find an accurate retardation plate. The cost of polishing an entire batch of crystal parts (quartz, magnesium fluoride, sapphire, etc.) will make the prices of low quantities of these retarders very expensive. Using our polymer processing facilities, Meadowlark Optics can create a custom retarder for your specific wavelength. Custom retardances, such as eighth-wave or tenth-wave are also available. We also have the ability to create retarders with custom dimensions or large areas to perfectly within your unique optical design.
Other distinctive retarders that Meadowlark Optics can produce include a product we call Micro Retarders. These components were originally designed for use inside telecommunications systems and their primary characteristic is their thickness, or more appropriately their thinness. These retarders measure less than 20 microns thick, less than five millimeters per side and have almost perfect transmission characteristics. Like our standard polymer retarders these parts are available for any wavelength and any retardance.
Our longitudinal Pockels Cells are often used in polarimetry on imaging light beams and in the chopping of polarized beams. They consist of Z-cut KD*P crystals between protective windows that have transparent indium-tin oxide electrodes applied to their interior faces. The electrodes produce a uniform electric field normal to the optical faces and permit use of a thin (less than 3 mm) KD*P crystal. This makes these cells suitable for use in non-collimated imaging light beams slower than f/20. Meadowlark specializes in clear apertures’ up to 40 mm. These devices are useful as variable retarders in applications requiring much faster switching.

Over the years Meadowlark Optics has been asked to deliver some unique polarization components. Our reputation for quality and innovation has made us the company that many people turn to when they need a device that is not readily available.

Examples of these devices include a segmented polarizer that contained four different quadrants, where each quadrant had its polarization transmission axis in a different orientation. Another is an assembly of polarizing beamcubes that can take an input beam and separate it into multiple output beams with varying linear polarization directions. We also have manufactured an optically addressed spatial light modulator. Our engineers have spent years designing these components for various applications and they have the imagination and knowledge to build a component that will perfectly fit your needs. So, if you have an idea for a polarization component that you cannot find anywhere else, talk to Meadowlark Optics.