What we've done
Here are a few of the hundreds of jobs we’ve completed in the past 23 years:
LED-Powered PAR 64
Standard “light bulbs” for aircraft and military vehicles have short lifetimes and low efficiency. Replacing them with LED-powered components presents severe thermal and spatial design problems. SSG designed a light source that fits in to the very same volume, and that runs at a safe temperature. A unique segmented optic takes advantage of the LED’s emission pattern to fit in the limited space, but still allow for conductive cooling. The output beam copies the standard beam shape, with higher intensity, lower power and much longer life.
TV and Movie Lights
The entertainment industry needs light – lots of it. Illuminating a movie or TV set calls for big lamps, big fixtures, and big power supplies. To get light from a high-power arc lamp to a rectangular set – a set the shape of a TV or movie screen – we need to design a light fixture that directs as much light as possible into that rectangle. In this picture is a split trough design for a long Xenon arc lamp. Light from the reflector could bounce forward through the linear arc lamp, where it can be reabsorbed. To avoid this dangerous and damaging geometry, SSG designed a split reflector that takes light above and below the lamp. SSG has designed many TV and movie fixtures, not only for the usual box format, but also for huge Fresnel spot lights and for special effects like lightning and explosions.
Hardware in Spacecraft follows ultraconservative design rules, for the safety of the structure and for the lives of the Astronauts. All components must be well-known, much-tested, no surprises. This project called for tungsten-filament lamps that had been proven reliable in flight. Not optimum for the lighting tasks, but totally safe in the space environment. The job – to partner with TV cameras at several stations on movable arms controlled from within the Space Station. A multi-segment nickel electroform did the job. SSG’s detailed coordinate list of radius versus axial length defined the contour. The manufacturer used this to create a polished mandrel for electroforming the reflector, shown with a 3-inch marble “Globe”.
Throughout the world, work continues on the “big-physics” attempt to develop laser fusion energy by inertial confinement – squeezing a small amount of material together until its density triggers nuclear fusion. Light beams converge to “push” on the target sphere evenly from many sides. This is really an illumination problem. Each beam passes through a large aspheric lens, carefully ground and polished to exacting specifications for material purity and shape. The lens and its anti-reflection coating must survive repeated pulses of high energy, This one, designed by SSG, is part of a multi-beam laser fusion research system.
Many of the jobs we work on are practical, everyday gadgets that employ light to perform some useful, everyday task. Health Inspectors and Policemen both use ultraviolet light to find information not available to the human eye. Here are some pictures of UV flashlight performance tests, and a typical target photograph.
Two ultraviolet zoom flashlight designs are compared on a fluorescent measuring target.
The UV LED source in both flashlights is a matrix of radiating squares and edge lines.
A partial fingerprint on a shotgun shell is readily visible with UV light. In many crime scene situations, detectives must first spray the questioned materials with fluorescence-enhancing liquid, then turn off visible light and use only UV to search for evidence.
Do you need to see something very small? Do you want to see more surface detail? Looking for 3-D information? In illumination design, a critical measure of efficiency is the quality of a reflector surface. SSG has a Zeiss Nomarski microscope, the ideal tool for viewing reflective surfaces. It converts height differences into color differences by light interference. We can use it on any opaque object that needs high magnification and contour measurement. Forensic problems can sometimes be solved by looking at fine surface detail, manufacturing problems too.
Call SSG - We may be able to give you the pictures and measurements you want.
Example 1 - forensic evidence
Example 2 - semiconductor processing
The upper photo shows a cross-section of a silicon structure intended to hold and align parallel optical fibers. The cutting and polishing machinery cracked the sharp points of the grooves, and left jagged edges along the fiber direction. This 160X Nomarski photo shows also that the end cut was not flat, because the pink color shaded into green, revealing about a 2 micron curvature.
After the process was improved, the lower photo shows a slice through the entire assembly; The silicon substrate, bottom, is white. The fibers are light green, and the epoxy holding the fibers in their grooves is dark green.
Example 3 - medical instruments
Medical instruments need special inspection techniques to insure that instrument surfaces are smooth enough to contact sensitive surfaces like the interior of blood vessels.