A double-channel planar buried hetero-structure (DCP BH) has a planar active region, the confinement material is?
A four-port FBT coupler has 60Î¼W optical power launched into port one. The output powers at ports 2, 3, 4 are 0.0025, 18, and 22 Î¼W respectively. Find the split ratio?
A four-port multimode fiber FBT coupler has 50 Î¼W optical power launched into port 1. The measured output power at ports 2,3 and 4 are 0.003, 23.0 and 24.5 Î¼W respectively. Determine the excess loss.
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.
A perfect semiconductor crystal containing no impurities or lattice defects is called as __________
A _____________ coupler comprises a number of cascaded stages, each incorporating three or four-port FBT couplers to obtain a multiport output.
As compared to planar LED structure, Dome LEDs have ______________ External power efficiency ___________ effective emission area and _____________ radiance.
1.Greater, lesser, reduced
2.Higher, greater, reduced
3.Higher, lesser, increased
4.Greater, greater, increased
1.Multi Quantum well lasers
2.Single Quantum well lasers
3.Gain guided lasers
Buried hetero-junction (BH) device is a type of _____________ laser where the active volume is buried in a material of wider band-gap and lower refractive index.
2.Gain guided lasers.
3.Weak index guiding lasers.
4.Strong index guiding lasers.
Calculate the splitting loss if a 30Ã—30 port multimode fiber star coupler has 1 mW of optical power launched into an input port.
1.More coupled optical power
2.Less coupled optical power
3.Low current densities
4.Low radiance emission into-fiber
4.Gain guided lasers
3.Outside the strip
4.Both transverse and lateral direction
In multimode injection lasers, the construction of current flow to the strip is obtained in structure by __________
1.Covering the strip with ceramic
3.Implantation outside strip region with protons
4.Implantation outside strip region with electrons
1.Cannot be determined
1.Optical fiber coupler
2.Optical fiber splice
3.Optical fiber connector
1.To reduce radiance
2.To increase radiance
3.To reduce current spreading
4.To increase current spreading
3.Gain guided lasers
1.Through regrowth of semi-insulating material
2.By using oxide material
3.By using a planar InGaAsP active region
4.By using a AlGaAs active region
3.Conventional DH devices
The energy-level occupation for a semiconductor in thermal equilibrium is described by the __________
1.Boltzmann distribution function
2.Probability distribution function
3.Fermi-Dirac distribution function
4.Cumulative distribution function
1.Length strip geometry
4.Coupled optical power
1.Numerical apertures of fibers
2.Varying refractive index of fibers
3.Angular power distribution at source
4.Number of modes propagating in each fiber
The overall power conversion efficiency of electrical lens coupled LED is 0.8% and power applied 0.0375 V. Determine optical power launched into fiber.
The techniques by Burros and Dawson in reference to homo structure device is to use an etched well in GaAs structure.
The _______ method is the most commonly used method for the determination of the fiber refractive index profile.
1.Refracted near-field method
3.Power step method
4.Alternative test method
1.Refractive index is decreased
2.Doping the material with impurities
3.Increase the band-gap of the material
3.Less than 10 Î¼m
When considering source-to-fiber coupling efficiencies, the ________ is an important parameter than total output power.
2.Radiance of an optical source
4.Angular power distribution
1.Wavelength division multiplexing
2.Lateral offset method
3.Semitransparent mirror method
4.Fused bi-conical taper (FBT) technique
________ couplers combine the different wavelength optical signal onto the fiber or separate the different wavelength optical signal output from the fiber.
_______________ method does not require a leaky mode correction factor or equal mode excitation.
2.Power step method
3.Alternative test method
4.Refracted near-field method
_________________ is used when the optical emission results from the application of electric field.