Optical soliton generator
AssigneeAT&T Corp.
InventorsSteven K. Korotky, John J. Veselka
Life of this patent
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Abstract
An optical pulse generator for producing a soliton pulse train having a modulator which amplitude and phase modulates an optical frequency output of a continuous optical wave source. The modulator is driven by first and second harmonically related continuous sinusoidal waves from first and second CW voltage sources and the generator includes a pulse compression means for producing at the output of the generator a soliton pulse train.
Claims19
Apparatus for generating a soliton pulse train comprising return-to-zero pulses having a repetition frequency of f, said apparatus comprising:
- a source of continuous wave optical signal;
- modulator means having an input for receiving the optical signal and producing an optical pulse output, said modulator means comprising means for amplitude modulating and phase modulating the optical signal;
- a first voltage source for applying a first continuous wave sinusoidal modulating voltage having a first frequency to said modulator means;
- a second voltage source for applying a second continuous wave sinusoidal modulating voltage having a second different frequency harmonically related and phase locked to the first sinusoidal modulating voltage to said modulator means;
- and
- optical pulse compression means having an input and an output for receiving the optical signal to produce said pulse train at its output.
A soliton pulse generator having an output comprising:
- a source of a continuous wave optical signal;
- a first modulator having an input connected to the output of said source and an output;
- a first source of a continuous wave sinusoidal modulating voltage at a frequency f electrically connected to said first modulator means;
- a second modulator having an input and an output and having a cosine.sup.2 transfer function;
- a second source of a continuous wave sinusoidal modulating voltage at a frequency f/2 electrically connected to said second modulator means;
- the modulating voltages from said first and second sources being phase-locked together;
- pulse compression means having an input and an output with its input being connected to at least one of the said outputs of said first and second modulator means producing at the output of the pulse generator a pulse train having a ratio of pulse period T to pulse full width at half maximum .tau. greater than three (T/.tau.>3).
A method of generating a soliton pulse train comprising:
- generating a continuous wave optical signal;
- producing a return-to-zero pulse train having a ratio of pulse period T to pulse with t of approximately 3 (T/t.congruent.3) where T is the reciprocal of the pulse repetition frequency f and t is the pulse full width at half maximum (FWHM) by amplitude modulating the optical signal with a first continuous sinusoidal signal of frequency f/2;
- broadening the spectral width of the pulses in the pulse train by phase modulating the optical signal with a second continuous sinusoidal signal of a greater frequency that is harmonically related to the frequency of the first signal and is phase locked thereto;
- and
- increasing the ratio of pulse period T to pulse width t to a value greater than 3 by compressing the pulses in the pulse train.
Dependencies are inferred from the claim text.