Compound semiconductors

What material is used for the blue-violet semiconductor laser of about 405 nm that reads and writes Blu-ray discs?

  1. AGaN-based
  2. BGaAs-based
  3. CInP-based
Show answer and explanation

Answer: A. GaN-based

Blu-ray uses a blue-violet laser of about 405 nm, and the laser diode is made of GaN-based materials. Shorter wavelengths can be focused to smaller spots, allowing higher recording density than DVDs, which use red lasers. GaAs-based materials are used for red to infrared lasers and InP-based for infrared lasers for optical communication.

  • A. Correct. Blue-violet lasers are made from GaN-based materials.
  • B. GaAs-based materials are used for red to infrared lasers.
  • C. InP-based materials are used for 1.3–1.55 µm optical communication lasers.
Practice this topic Back to topic

More Compound semiconductors questions

  1. Which material, whose band gap can be tuned by composition, has been used for high-performance mid- to long-wave infrared detectors?
  2. Which is one reason it is difficult to build silicon-like CMOS circuits in GaAs?
  3. How is silicon germanium (SiGe) classified?
  4. What is a high-frequency IC called that integrates transistors together with passive components such as inductors and capacitors on a substrate such as GaAs?
  5. What is the empirical rule called that says the lattice constant of an alloy semiconductor such as AlGaAs varies almost linearly with composition?