Patent ID: 7236661
Filing Date: 2007-06-26
Classification: G02B,H04B

Abstract:
1. A tunable dispersion compensation apparatus comprising: a light path from an input block to an output block, the input block configured to input an optical signal to the light path, the output block configured to output the optical signal from the light path; a circulating light path upon the light path; a dispersion element that has wavelength dispersion characteristics; a wavelength shifter configured to shift a wavelength of the optical signal on the circulating light path: a controller configured to control an amount of shift of the wavelength shifter depending on the inputted optical signal or to control the dispersion characteristics of the dispersion element for providing a required dispersion value for a compensation; means for circulating the inputted optical signal around the circulating light path a stipulated number of times determined based on the amount of shift of the wavelength shifter controlled by the controller before the optical signal is output by the output means, wherein the light path is provided with a first circulator and a second circulator; the circulating light path is a loop-shaped path connecting the second circulator and the wavelength shifter; the optical signal inputted to the light path from the input block passes through the first circulator and the dispersion element, circulates around the loop-shaped light path and passes through the dispersion element and the first circulator in the light path until reaching the output block; and the dispersion element has a reflection band intermediate between a wavelength of the inputted optical signal and a wavelength of the optical signal reaching the output block.