Compression of generated optical continuum utilizing higher-order-mode fiber

A method of compressing optical pulses comprising the steps of:

• a) generating a spectrally broadened optical continuum signal at a fundamental mode;
• b) converting the optical continuum signal to a higher order mode signal over an operable wavelength range (λa-λb);
• c) launching the converted signal of step b) into a section of higher-order mode (HOM) fiber with a dispersion and length selected to compensate for accumulated spectral phase present along a defined bandwidth (λ1-λ2);
• d) filtering the optical signal to remove wavelengths beyond preferred wavelength ranges associated with the operation of steps b) and c), the removed wavelengths being less than a first defined wavelength λiand greater than a second defined wavelength λii, where
• λi≧λ1,λa;
• and
• λii≦λ2,λb.
• and;
• e) creating compressed optical pulses at the output of the section of HOM fiber.

An optical pulse source for generating sub-picosecond width optical pulses, comprising

• an optical continuum signal generator including a source of input pulses at a first wavelength coupled to a section of highly-nonlinear fiber for generating a spectrally-broadened optical continuum output signal;
• an input mode converter disposed beyond an output of the optical continuum signal generator for converting the fundamental mode of the generated optical continuum signal to a higher order mode optical continuum signal, the input mode converter having an operable bandwidth (λa-λb);
• a section of higher-order mode fiber coupled to an output of the input mode converter, the section of higher-order mode fiber having a large effective area and exhibiting a predetermined dispersion characteristic across a bandwidth (λ1-λ2) that overlaps, at least in part, the optical continuum signal bandwidth so as to create a pulsed optical output signal having a sub-picosecond pulse width;
• and
• a bandpass filter for limiting the optical pulse source output to include dispersion-compensated compressed optical pulses, the bandpass filter having a passband (λi-λii) where
• λi≧λ1,λa;
• and
• λii≦λ2,λb.