Prоblem 1 1а. Whаt 3 fundаmental prоcesses affect the behaviоr of lasers, and of those, which process gives rise to lasing? 1b. What is the effect of photonic cavity in a laser? 1c. What is the advantage of a 4-level laser system over a 3-level laser system? Problem 2 2a. What is Kirchoff’s law of thermal radiation? 2b. What are the three major thermal transport processes, and how does each one scale with temperature? 2c. If the temperature of a blackbody is 3000 K, at what wavelength will its emission reach a peak? Problem 3 3a. What is thermophotovoltaics? Mention one benefit and one limitation. 3b. What are selective thermal emitters? Problem 4 4a. Mention one advantage and one disadvantage of quadratic finite elements compared to linear finite elements. 4b. How does a photonic crystal fiber work? Congratulations, you are almost done with Exam 4. DO NOT end the Examity session until you have submitted your work to Gradescope. When you have answered all questions: Use your smartphone to scan your answer sheet and save the scan as a PDF. Make sure your scan is clear and legible. Submit your PDF to Gradescope as follows: Email your PDF to yourself or save it to the cloud (Google Drive, etc.). Click this link to go to Gradescope: https://www.gradescope.com/courses/695047 Submit your exam to the assignment Exam 4. Return to this window and click the button below to agree to the honor statement. Click Submit Quiz to end the exam. End the Examity session.