Increasing Transfer Rate and Capacity in Optical Data Storage through Pit Depth Modulation

The use of pit depth modulation (PDM) in optical data storage historically has received little attention; the only known literature to the authors is cited below in references 1-5. However, considerable improvements to both disc capacity and transfer rate can be realized by its implementation. Unlike many methods that improve disc capacity, PDM has the advantage of increasing data transfer speed in direct proportion to obtained increases in data capacity. It is also compatible with other innovations under development, including smaller pits read by shorter wavelength lasers and higher NA lenses, faster disc spin-rates, and double-sided, dual depth or multilayer discs. Performance improvements from PDM are additional to those achieved from other innovations.