Patent ID: 8428413

Claim:
A stretcher fiber, comprising: a core region having a radius r 1 , a refractive index n 1 , and a positive refractive index difference Δn 1 with respect to an outer cladding region having an outer radius r 0 and a refractive index n 0 , where Δn 1 is equal to n 1 −n 0 , an inner trench region surrounding the core region, the trench region having an outer radius r 2 , a refractive index n 2 less than n 0 , and a negative refractive index difference Δn 2 equal to n 2 −n 0 , a ring region surrounding the trench region, the ring region having an outer radius r 3 , a refractive index n 3 greater than n 0 , and a positive refractive index difference Δn 3 equal to n 3 - n 0 , an outer trench region surrounding the ring region, the outer trench region having an outer radius r 4 , a refractive index n 4 less than n 0 , and a negative refractive index difference Δn 4 equal to n 4 −n 0 , the outer cladding region surrounding the outer trench region, wherein the values of r 0 , r 1 , r 2 , r 3 , r 4 , Δn 1 , Δn 2 , Δn 3 , and Δn 4 are structured to provide the stretcher fiber with a relationship between dispersion and wavelength, wherein the stretcher fiber β 2 and β 3 /β 2 curves have a shape and wavelength range matching those of a selected compressor module, wherein β 2 is the second derivative of the stretcher fiber's propagation constant β with respect to angular frequency ω: β 2 = ⅆ 2 ⁢ β ⅆ ω 2 , and wherein β 3 is the third derivative of the selected fiber's propagation constant β with respect to angular frequency ω: β 3 = ⅆ 3 ⁢ β ⅆ ω 3 .