________ couplers combine the different wavelength optical signal onto the fiber or separate the different wavelength optical signal output from the fiber.

Related MCQs

• A number of three-port single-mode fiber couplers are used in the fabrication of a ladder coupler with 16 output ports. The three-port couplers each have an excess loss of 0.2 dB along with a splice loss of 0.1 dB at the interconnection of each stage. Determine the excess loss.
• If the input power 100μW is launched into 6 km of fiber, the mean optical power at the fiber output is 2μW. What is the overall signal attenuation through the fiber assuming there are no connectors or splices?
• . When the input and output power in an optical fiber is 120μW & 3μW respectively and the length of the fiber is 8 km. What is the signal attenuation per km for the fiber?
• A single-mode optical fiber has an attenuation of 0.3dB/km when operating at wavelength of 1.1μm. The fiber core diameter is 4μmand bandwidth is 500 MHz. Find threshold optical power for stimulated Brillouin scattering.
• In optical fiber communication, the electrical signal dropping to half its constant value due to modulated portion of optical signal corresponds to _______
• Optical fiber couplers are also called as ________________
• How many types of multiport optical fiber couplers are available at present?
• In a GaAs LED, compute the loss relative to internally generated optical power in the fiber when there is small air gap between LED and fiber core. (Fiber coupled = 5.5 * 10-4Pint)
• An FBG is developed within a fiber core having a refractive index of 1.30. Find the grating period for it to reflect an optical signal with a wavelength of 1.33μm.
• . A decibel may be defined as the ratio of input and output optical power for a particular optical wavelength. State whether the following statement is true or false.