Sony demos ‘cheap’ holographic recording technique

border=0>Sony is showing off its “Micro-Reflector recording” technique which uses an off-the-shelf blue violet semiconductor laser diode for writing data to a 0.3 millimeter-thick photopolymer medium sandwiched by 0.6 millimeter-thick glass substrates without any of the spatial light modulators or CMOS sensors found in traditional holographic systems.

face=Verdana>How do they achieve this nifty feat, you ask? Simple: the laser beam is “split into two so that one of them irradiates the front side of a medium as a reference light while the other is emitted to the backside as a recording light. By precisely aligning focal points of the two lights with a servo technology, a minute interference fringe corresponding to a 1 bit recording mark is formed. When a laser light (reproduction light) is emitted on the front side of the medium having interference fringes, the recording light is reproduced. This light advances from the fringes to the medium front side as if the fringes reflect the reproduction light.”