Multi-Beam Read-Verifying Optical Head for Parallel Recording

A five-beam read-only optical head using a holographic beam splitter has been developed for instantaneous read-verification of parallel data recording. The holographic grating made of photo-resist film splits a 680-nm laser beam into five diffracted beams and an interval angle of 4 mrad. The average...

Full description

Saved in:
Bibliographic Details
Published in:JPN J APPL PHYS PART 1 REGUL PAP SHORT NOTE REV PAP 1993, Vol.32 (11B), p.5406-5410, Article 5406
Main Authors: WATABE, A, TANABE, T, MURATA, S, KATOH, K
Format: Article
Language:English
Subjects:
Applied sciences
Electronics
Exact sciences and technology
Magnetic and optical mass memories
Storage and reproduction of information
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A five-beam read-only optical head using a holographic beam splitter has been developed for instantaneous read-verification of parallel data recording. The holographic grating made of photo-resist film splits a 680-nm laser beam into five diffracted beams and an interval angle of 4 mrad. The average diffraction efficiency of the beams is about 13% and their spot diameters are 1.05±0.03 µm within a 70-µm image circle. A newly designed objective lens system composed of an aspherical lens and a chromatic lens can compensate 680 nm to 780 nm of chromatic aberration of wavelength to less than 0.4 µm. The carrier to noise (C/N) ratio of a 1.53-µm-pitch voltage-controlled frequency oscillation (VFO) signal is 49 dB, which is sufficient for magneto optical (MO) disk data retrieval.
ISSN:0021-4922
1347-4065
DOI:10.1143/JJAP.32.5406