1. Herb Kroemer Optical Patents: The alpha and the omega… 1 Kroemer Symposium John Bowers May 20, 2013

2. Herb’s First Optical Patent: Double Heterostructure Laser Filed: 1963 Issued: 1967 Expired: 1985 Patent 3,309,553

3. Double Heterostructure Laser Diode: The first cw semiconductor laser Izuo Hayashi (left) and Morton Panish (1971) at Bell Labs were able to design the first semiconductor laser that operated continuously at room temperature. The need for semiconductor heterostructures for efficient laser diode operation was put forward by Herbert Kroemer. (Reprinted with permission of Alcatel–Lucent USA Inc.)

4. M. B. Panish et al. APL 16(8), 1970 400x

5. Carrier confinement HeterojunctionHomojunction Higher optical losses

6. HeterojunctionHomojunction Index profile Intensity profile 1% 10%  n : the difference in the reflective index d : the thickness of the active layer, C : Constant Optical confinement

7. 7 How Important is this Invention?

8. 8 About $4B annually Laser Focus World Jan. 2013 All commercial diode lasers use double heterostructures Herb’s patent runs out

9. 9 Herb’s second optical patent Light-emitting structures in silicon are more attractive from a fabrication standpoint…light generation in silicon is an inefficient process…

10. Herb’s Latest Optical Patent: Optical Isolator

11. Hybrid Silicon Ring Isolator Tien et al. “Silicon ring isolators with bonded nonreciprocal magneto-optic garnet” Optics Express (2011). First experimentOptimized design

12. Herb: Thank you! For your insights For setting high standards in research, and faculty and students recruiting For tolerating my research on hybrid III-V silicon photonics…the gain is in the III-V after all, not like those MIT guys…and you were 45 years ahead anyway. 12