| US 7,403,142 B2 | ||
| Optical quantizing unit and optical A/D converter | ||
| Masatoshi Hirono, Yokohama (Japan); Takahiro Suzuki, Tokyo (Japan); Hideki Ito, Kawasaki (Japan); and Takeshi Morino, Tokyo (Japan) | ||
| Assigned to Kabushiki Kaisha Toshiba, Tokyo (Japan) | ||
| Filed on Sep. 25, 2006, as Appl. No. 11/525,842. | ||
| Claims priority of application No. 2006-004214 (JP), filed on Jan. 11, 2006. | ||
| Prior Publication US 2007/0166044 A1, Jul. 19, 2007 | ||
| Int. Cl. H03M 1/00 (2006.01) | ||
| U.S. Cl. 341—137 [341/155] | 1 Claim |
| 1. An optical A/D converter comprising:
an optical sampling unit which samples an optical analog signal and converts the optical analog signal into a string of first
optical pulses;
an optical quantizing unit which quantizes each of the first optical pulses so as to generate a string of guantized second
optical pulses and outputs the quantized second optical pulses, a number of the guantized second optical pulses depending
on light intensities of the first optical pulses; and
a binary converter which performs binary conversion of the quantized second optical pulses,
wherein the optical quantizing unit includes
an optical divider which divides the first first optical pulses to be quantized and transmits the divided first optical pulses
to a plurality of paths, respectively;
a plurality of optical filters which transmit with different transmittances each of the divided first optical pulses, respectively;
an optical synthesizer which synthesizes each of the divided first optical pulses passed through each of the optical filters;
and
an optical threshold filter which sequentially receives each of the divided first optical pulses that passed through each
of the optical filters from the optical synthesizer, and outputs the quantized second optical pulses when light intensities
of the divided first optical pulses passed through the optical filters are above a preset threshold value.
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