Patent ID: 7756385

Claim:
An antisqueezed light generator constructed of an optical system, the system comprising: a laser light source; an intensity modulator that modulates output light from the laser light source into pulsed light (let ΔT denote a full width at half maximum with respect to a pulse time width in such event); an optical amplifier for amplifying the pulsed light (let P o denote a peak power after amplification); a first optical fiber that has an negative group-velocity dispersion at a operating wavelength λ of the laser light source; and a second optical fiber with a smaller negative group-velocity dispersion in absolute value than that of the first optical fiber, wherein each parameter of ΔT, P o , and β 2 are set in such a manner that soliton order N, given by an equation N 2 =γP o T o 2 /|β 2 | from a pulse width T o defined by T o =ΔT/(2×0.88137), the group-velocity dispersion β 2 of the first optical fiber at the operating wavelength λ, and an nonlinear coefficient γ of the first optical fiber at the λ, becomes 2 or more, a length of first optical fiber is set within a range of 60 to 150% of the fiber length z opt =z o (0.32/N+1.1/N 2 ) determined from the soliton order N after each parameter is set and from the soliton period z 0 =(π/2)T 0 2 /|β 2 |, a length of the second optical fiber is within a range from 1 km to 100 km, and the light whose noise is expanded in a phase direction is eventually outputted.