US 7,352,504 B2 · Optical fourier transform device and method

Abstract

Optical Fourier transform is executed over a wide time range. A quadratic function type optical pulse generator (7) generates a control light pulse of a shape expressed by a quadratic function or a parabola according to a clock signal based on a signal light pulse from an optical coupler (1). The signal light pulse inputted is multiplexed by a multiplexer (9) with the control light pulse optically delayed by an optical delay element (8) so that the timing is matched with the signal light pulse, and introduced into an optical Kerr medium (10). In the optical Kerr medium (10), the signal light pulse inputted by the mutual phase modulation between the signal light pulse and the control light pulse is subjected to a linear phase modulation (frequency chirp) over the entire pulse or a wide time range. After that, the signal light pulse isolated by an optical filter (11) is introduced into the dispersion medium (12) having a group velocity dispersion (secondary dispersion), thereby converting the time waveform of the inputted signal light pulse into the shape of the frequency spectrum.

Claims18

Dependent claims

An optical Fourier transform device comprising:

a parabolic optical pulse generator to generate a control optical pulse of a shape expressed by a quadratic function or a parabola;
a coupler to couple a signal optical pulse with the control optical pulse;
an optical Kerr medium to linearly chirp the signal optical pulse over an entire pulse, or a wide time range by cross phase modulation between the signal optical pulse and the control optical pulse;
and
a dispersive medium having a group-velocity dispersion, wherein the launched signal optical pulse and the control optical pulse are coupled by the coupler and are introduced into the optical Kerr medium, the launched signal optical pulse is linearly chirped at a chirp rate K by the optical Kerr medium by the cross phase modulation between the signal optical pulse and the control optical pulse, the signal optical pulse emitted from the optical Kerr medium is made to pass through the dispersive medium whose dispersion amount D is D=1/K, to convert a temporal waveform of the launched signal optical pulse into a shape of a frequency spectrum thereof.

2 more elements

An optical Fourier transform device comprising:

a parabolic optical pulse generator to generate a control optical pulse of a shape expressed by a quadratic function or a parabola;
a coupler to couple a signal optical pulse with the control optical pulse;
an optical Kerr medium to linearly chirp the signal optical pulse over an entire pulse or a wide time range by cross phase modulation between the signal optical pulse and the control optical pulse;
and
a dispersive medium having a group-velocity dispersion, wherein the parabolic optical pulse generator comprises:
a optical pulse transmitter to generate a optical pulse;
and
a dispersion-decreasing fiber in which an absolute value of a normal dispersion is decreased in a longitudinal direction, wherein
the launched signal optical pulse is made to passes through the dispersive medium, the signal optical pulse emitted from the dispersive medium and the control optical pulse are coupled by the coupler and are introduced into the optical Kerr medium, the signal optical pulse emitted from the dispersive medium is linearly chirped by the optical Kerr medium by the cross phase modulation between the signal optical pulse and the control optical pulse, to convert a shape of a frequency spectrum of the launched signal optical pulse into a temporal waveform.

6 more elements

An optical Fourier transform device comprising:

a parabolic optical pulse generator to generate a control optical pulse of a shape expressed by a quadratic function or a parabola;
a coupler to couple a signal optical pulse with the control optical pulse;
an optical Kerr medium to linearly chirp the signal optical pulse over an entire pulse or a wide time range by cross phase modulation between the signal optical pulse and the control optical pulse;
and
a dispersive medium having a group-velocity dispersion, wherein the parabolic optical pulse generator comprises:
an optical pulse transmitter to generate a optical pulse;
and
a dispersion-decreasing fiber in which an absolute value of a normal dispersion is decreased in a longitudinal direction, wherein the launched signal optical pulse and the control optical pulse are coupled by the coupler and are introduced into the optical Kerr medium, the launched signal optical pulse is linearly chirped by the optical Kerr medium by the cross phase modulation between the signal optical pulse and the control optical pulse, the signal optical pulse emitted from the optical Kerr medium is made to pass through the dispersive medium, to convert a temporal waveform of the launched signal optical pulse into a shape of a frequency spectrum thereof.

5 more elements

Dependencies are inferred from the claim text.

Optical fourier transform device and method

Life of this patent

Optical fourier transform device and method

Life of this patent

Abstract

Claims18