The fluorescence- and transmittance-detection readout methods of a near-field photochromic optical memory by a scanning-probe technique were studied theoretically. Shot noise, as the principal noise, was taken into account in an analysis of the signal-to-noise ratio (SNR). Under most conditions, fluorescence-detection readout yielded a better SNR than did transmittance-detection readout. For a transmittance change of 0.9–1.0 as a result of recording, a readout light power of approximately 100 nW, and a system bandwidth of 1 MHz, only the fluorescence-detection readout method, under the condition that the fluorescent layer of the medium have a fluorescence quantum yield greater than 0.4, can produce a sufficiently large SNR.
© 1998 Optical Society of America
(210.0210) Optical data storage : Optical data storage
(210.4680) Optical data storage : Optical memories
(210.4770) Optical data storage : Optical recording
(260.2510) Physical optics : Fluorescence
Tsuyoshi Tsujioka and Masahiro Irie, "Fluorescence Readout of Near-Field Photochromic Memory," Appl. Opt. 37, 4419-4424 (1998)