Patent ID: 8737778
Filing Date: 2014-05-27
Classification: G02B

Abstract:
1. A variable optical attenuator comprising: a mirror supported to assume a variable range of positions; a lens; an input optical fiber for transmitting light comprising an optical signal through the lens to the mirror, wherein the input optical fiber is a cladding mode suppressing fiber, and wherein the input optical fiber is a double clad fiber and comprises a core, an inner cladding, and an outer cladding, wherein the core of the input optical fiber has a higher index of refraction than the inner cladding of the input optical fiber, and wherein the outer cladding of the input optical fiber has a higher index of refraction than the inner cladding of the input optical fiber; an output optical fiber for receiving light reflected from the minor and focused through the lens comprising at least a core and an inner cladding, wherein the output optical fiber is a cladding mode suppressing fiber for suppressing cladding modes in the inner cladding of the output optical fiber over a length of the output optical fiber and for, thereby, reducing a polarization dependent loss and a wavelength dependent loss of the variable optical attenuator, wherein the length of the output optical fiber is greater than 15 mm and less than 100 cm; and an electro-static actuator for controlling a position of the mirror such that a selected portion of the light reflected from the minor is focused through the lens into the core of the output optical fiber, while a remaining portion of the light reflected from the minor is coupled into the inner cladding of the output optical fiber, in dependence on the position of the mirror; wherein the variable optical attenuator is housed in a small form factor module.