Process and device for measuring the complex spectrum (amplitude and phase) of optical pulses

Claim 1

A device for determining a phase relation of a signal having a spectrum including a spectral component at a central optical frequency f 0 and spikes at frequencies f n =f 0 ±nF, where n is an integer and F is a predetermined frequency, the device comprising: a modulator adapted to receive the signal; a frequency divider adapted to receive a signal of the predetermined frequency; a variable delay coupled between the frequency divider and the modulator; a tunable filter coupled to the modulator; and a photoreceiver coupled to the tunable filter, wherein the device produces signals representative of phase differences between two spikes in pairs of adjacent spikes of the spikes at the frequencies f n =f 0 ±nF.

Claim 2

A device for determining a phase relation of a signal having a spectrum including a spectral component at a central optical frequency f 0 and spikes at frequencies f n =f 0 ±nF, where n is an integer and F is a predetermined frequency, the device comprising: a modulator adapted to receive the signal; a frequency divider adapted to receive a signal of the predetermined frequency; a variable delay coupled between the frequency divider and the modulator; a tunable filter coupled to the modulator; and a photoreceiver coupled to the tunable filter, wherein the device produces signals representative of phase differences between two spikes in pairs of adjacent spikes of the spikes at the frequencies f n =f 0 ±nF.

Claim 4

The device of claims 1 or 2, wherein the modulator, the frequency divider and the variable delay are adapted to convert two spikes, f n and f n+1 , into two spikes having frequencies f n +0.5F, and the tunable filter and the photoreceiver are adapted to produce a signal representative of a phase of an interference signal between the two spikes having frequencies f n +0.5F.

Claim 14

The device of claims 11 or 12, wherein the frequency device comprises one of an electro-absorbent modulator and a phase modulator.

Claim 15

A device for determining a phase relation of an optical signal having a continuous spectrum, comprising: a modulator adapted to receive the optical signal; a photreceiver adapted to receive the optical signal; a signal generator coupled to the photreceiver and adapted to generate a signal having a frequency F dependent on a spectrum sampling frequency; a variable delay coupled between the signal generator and the modulator a tunable filter coupled to the modulator; and a photodetector coupled to the tunable filter, wherein the device produces signals representative of a phase difference between a signal having frequency f n -F and a signal having a frequency f n +F for n sampling frequencies f n , and the frequency F is one half of the spectrum sampling frequency.

Claim 16

A device for determining a phase relation of an optical signal having a continuous spectrum, comprising: a modulator adapted to receive the optical signal; a photreceiver adapted to receive the optical signal; a signal generator coupled to the photreceiver and adapted to generate a signal having a frequency F dependent on a spectrum sampling frequency; a variable delay coupled between the signal generator and the modulator a tunable filter coupled to the modulator; and a photodetector coupled to the tunable filter, wherein the device produces signals representative of a phase difference between a signal having frequency f n -F and a signal having a frequency f n +F for n sampling frequencies f n , and the frequency F is one half of the spectrum sampling frequency.

Claim 18

The device of claims 14 or 15, wherein the modulator, the photoreceiver and the signal generator are adapted to modulate the signal with a continuous spectrum at the frequency F, and the tunable filter and the photodetector are adapted to produce a signal representative of a sum of intensities of the optical signal at frequencies f n -F and f n +F, for each sampling frequency f n .