Replication techniques for diffractive optical elements

In this work, we demonstrate mold replication with high aspect ratio patterns by Ni electro plating. Using the replicated mold, nano imprint lithography has been demonstrated.

https://iopscience.iop.org/article/10.1143/JJAP.41.4186/pdf

Nano-imprint lithography using replicated mold by Ni electro plating

A Bibliography of the Literature on Optical Storage Technology | NIST

Optical recording systems capable of information storage and retrieval, using a highly focused laser beam as the recording and playback source, have been developed to a point where product introduction in the 1983-1985 time frame is highly probable. The product protentials range from low-data-rate (10-20 Mbits/s), single disk (1010to 1011bits), random-access electronic office filing cabinets (augmenting existing word processing units) to high-date-rate (hundreds of megabits per second), multidisk (1013bits on line "jukeboxes"), random-acess archival mass memories. This article presents the basic features of these optical disk data storage and retrieval systems with particular emphasis on the recording source and recording media.

Optical recording: High-density information storage and retrieval

Apparatus for recording an information signal (25) on a recording medium such as a rotatable optical recording disc (11), operates such that the signal can subsequently be recovered from the disc with little second harmonic distortion. An intensity-modulated write beam of light (13) is focused onto the rotating disc to produce a sequence of spaced, non-reflective indicia, representative of the information signal, and a read beam of light (61) is focused onto the disc at a trailing location to produce a reflected read beam (69) that is modulated in intensity in accordance with the recorded pattern of non-reflective indicia. The duty cycle of the reflected read beam is monitored (71,83) and a corresponding dc bias signal (85) is utilised to controllably adjust either the peak intensity (at 15) or the modulation (at 53') of the write beam.

Apparatus and method for optically recording an information signal with reduced second harmonic distortion and a record so made

The mastering and replication of video discs is described. Mastering involves exposing a photoresist-coated plate to a focused, modulated laser beam. After development, a layer of nickel is grown on the photoresist surface. The nickel layer forms a negative copy of the master plate. This nickel copy may then be used to emboss into plastic sheet a positive replica of the original master. This paper emphasizes the critical parameters involved in the process.

P. Palermo

Papers

Video disc mastering and replication