How to form Images with the GLV
Since the GLV is a diffractive device, laser illumination is recommended (though any monochromatic light source such as LED may be used at reduced system throughput). The line illumination required by the GLV can be accomplished by a variety of methods. Typically, a "Powell lens" and collimator are used to transform a circular Gaussian beam into a top-hat profile. The line beam is focused onto the GLV to a width of <25um for best performance. Typical numerical apertures range from 0.01 to 0.1. The incident and reflected beams are easily separated by imposing a small incidence angle to the illumination (typically 5-15°).
During operation, the GLV modulates the light distribution in the diffracted orders. Contrast is generated using a transform- and inverse-transform lens pair. A spatial filter located in the Fourier plane between the lenses selects one or more of the transmitted orders for image formation. Typically GLV-based imaging systems use either the 0th order or the ±1st order(s). After the spatial filtering, the selected rays recombine on the screen or media to generate a borderless, high-contrast image.
The GLV module is driven by a controller board. In most cases, a custom controller is designed per application. However, Silicon Light Machines can supply a controller board for test purposes.
