VARIABLE OPTICAL DELAY MODULE

摘要

PROBLEM TO BE SOLVED: To provide an optical delay element for the purpose of causing an arbitrary time delay.

SOLUTION: The optical delay element causing an arbitrary time delay for optical signal control is composed of: a waveguide consisting of a chirp fiber grating (14) having a core in which a pitch with the refractive index modulated gradually changes; a temperature adjusting element (16) which is brought into longitudinal contact with the chirp fiber grating and capable of controlling temperature; and a control means which changes the pitch by the temperature control of the temperature control element to control the position of a reflection wavelength for every wavelength in the chirp fiber grating. Thus, the optical delay element can be made small in size and reduced in the number of components.

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