enhancement of the supercontinuum generation performance of a highly - nonlinear optical fiber is accomplished by incorporating at least one bragg grating structure in the hnlf . the bragg grating results in reflecting a core - guided signal into signal which also remains core - guided . the supercontinuum radiation generated by such an arrangement will exhibit a substantial peak in its energy at the grating resonance of the bragg grating and a region of increased radiation in a narrow wavelength band on the long wavelength side of the peak . a number of such bragg gratings may be formed so as to “ tailor ” the enhancements provided in the supercontinuum radiation . various , well - known bragg grating modifications may also be used in the inventive structure to enhance the generated supercontinuum .