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Optical pulse compressor, optical function generator, optical pulse compression method, and optical function generation method

Foreign code F110005732
File No. Y0368WO
Posted date Sep 12, 2011
Country United States of America
Application number 55364904
Gazette No. 20070025728
Gazette No. 7428096
Date of filing Mar 23, 2004
Gazette Date Feb 1, 2007
Gazette Date Sep 23, 2008
International application number JP2004003937
International publication number WO2004092810
Date of international filing Mar 23, 2004
Date of international publication Oct 28, 2004
Priority data
  • P2003-109708 (Apr 15, 2003) JP
  • 2004WO-JP03937 (Mar 23, 2004) WO
Title Optical pulse compressor, optical function generator, optical pulse compression method, and optical function generation method
Abstract (US7428096)
A small-sized, high-functionality optical pulse compressor capable of generating a low-power, high-repetition-frequency ultrashort pulse train used for ultrafast optical communication and photometry, and a simple-structure optical function generator for realizing an arbitrary time waveform.
The optical pulse compressor comprises and optical Fourier transform device (F) having an optical phase modulator ( 9 ) driven by the repetition-frequency of an input optical pulse train and a dispersive medium ( 8 ), for converting the shape of an input optical pulse frequency spectrum into its time waveform, and an optical filter ( 3 ) inserted ahead of the optical Fourier transform device (F), for reducing the spectrum width of an input optical pulse, wherein the optical Fourier transform device (F) converts a small-spectrum-width optical pulse output from the optical function generator generates an optical pulse.
The optical function generator generates an optical pulse having an arbitrary time waveform by reproducing, as it is, a spectrum waveform-shaped arbitrarily by an optical filter on a time-axis by the optical Fourier transform device (F).
Scope of claims [claim1]
1. An optical function generator comprising: an optical pulse generator for generating an optical pulse train;
an optical Fourier transform circuit for converting the shape of the frequency spectrum of the optical pulse input from the optical pulse generator to a time waveform, the optical Fourier transform circuit having an optical phase modulator driven at the repetition frequency of the input optical pulse train from the optical pulse generator and a dispersive medium;
and
an optical filter for shaping the spectrum of the input optical pulse and determining the time waveform of the output optical pulse in accordance with frequency characteristics, the optical filter being inserted before the optical Fourier transform circuit,wherein the optical Fourier transform circuit generates an optical pulse having a desired time waveform depending on the function form of the frequency characteristics of the optical filter, by reproducing, directly in the time domain, the spectrum shaped as desired by the optical filter.
[claim2]
2. An optical function generator according the claim 1, wherein a Fourier-transform-limited pulse is used as the input optical pulse.
[claim3]
3. An optical function generator according to claim 1, wherein the optical phase modulator is driven at a clock frequency reproduced from the input optical pulse train, and linearly chirps the input optical pulse;
and the dispersive medium gives group-velocity dispersion.
[claim4]
4. An optical function generator according to claim 1, wherein, in the optical Fourier transform circuit,the dispersive medium gives group-velocity dispersion to the optical pulse output from the optical filter;
the optical phase modulator is driven at a clock frequency reproduced from the input optical pulse train, and linearly chirps the optical pulse output from the dispersive medium;
and
the dispersive medium receives the optical pulse output from the optical phase modulator, gives group-velocity dispersion again, and compensates for the remaining chirp.
[claim5]
5. An optical function generator according to claim 1, wherein, in the optical Fourier transform circuit,the optical phase modulator is driven at a clock frequency reproduced from the input optical pulse train, and linearly chirps the optical pulse output from the optical filter;the dispersive medium gives group-velocity dispersion to the optical pulse output from the optical phase modulator;
and
the optical phase modulator receives the optical pulse output from the dispersive medium, gives another linear chirp, and compensates for the remaining chirp.
[claim6]
6. An optical function generator according to claim 1, wherein the chirp rate K of phase modulation by the phase modulator and the group-velocity dispersion D of the dispersive medium satisfy a relationship of K=1/D.
[claim7]
7. An optical function generation method using an optical function generator comprising an optical pulse generator, an optical Fourier transform circuit, and an optical filter, the optical Fourier transform circuit having an optical phase modulator and a dispersive medium, the optical function generation method including: shaping the spectrum of an input optical pulse from the optical pulse generator, and determining the time waveform of the output optical pulse in accordance with frequency characteristics, by inserting the optical filter before the optical Fourier transform circuit;driving the optical phase modulator at the repetition frequency of the input optical pulse train;
and
generating an optical pulse having a desired time waveform, depending on the function form of the frequency characteristics of the optical filter, by reproducing, directly in the time domain, the spectrum shaped as desired by the optical filter, by means of the optical Fourier transform circuit.
  • Inventor, and Inventor/Applicant
  • NAKAZAWA MASATAKA
  • HIROOKA TOSHIHIKO
  • JAPAN SCIENCE AND TECHNOLOGY AGENCY
IPC(International Patent Classification)
U.S. Cl./(Sub)
  • G02F001/055C
  • H01S003/00F1
  • H04B010/508
  • S02F203/26
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