ECE227A_final_solutions_final

ECE227A_final_solutions_final - Final ECE 227A December 8,...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Final ECE 227A December 8, 2010 Department of Electrical and Computer Engineering University of California, Santa Barbara # Students 6 5 4 3 2 1 <50 51-60 61-70 71-80 81-100 # Students 7 6 5 4 3 2 1 B B+ A- A Name_______________________________________
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 (35 pts) 1. A vertical cavity surface emitting laser design for operation at 1300 nm is shown in Figure 1. The laser needs to have AlAsSb/GaAlAsSb DBR mirrors, lattice matched to the InP substrate. A one wavelength cavity is used with InP intracavity contact/heat-spreaders on the edges, and an undoped InP region in the center that contains 5 InGaAs quantum wells. The quantum wells are 8 nm thick, and the barriers are 12 nm thick. The refractive index for the quantum wells is 3.55. For the DBR mirrors, assume index values of 3.00 and 3.30 for the AlAsSb and GaAlAsSb layers respectively (at 1300 nm). The metal-backed top mirror is assumed to have an amplitude reflectivity of 0.9979 (including mirror loss). The internal losses in the DBRs and the cavity region are assumed to be 18 cm -1 . The injection efficiency is measured to be 75%. 8 um diameter etched pillar VCSELs are formed, and the optical and carrier losses due to the aperture and pillar walls can be neglected. The effective index of the mode is 3.2. The light is measured through a 300 μ m thick InP substrate whose incremental propagation loss is 7 cm -1 . The substrate is AR coated on the bottom. a.
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 10

ECE227A_final_solutions_final - Final ECE 227A December 8,...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online