Upload
margaretmargaret-jordan
View
225
Download
2
Embed Size (px)
Citation preview
Herb’s First Optical Patent: Double Heterostructure Laser
Filed: 1963Issued: 1967Expired: 1985
Patent 3,309,553
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.)
0 0.4 0.8 1.2 1.60
5E+017
1E+018
1.5E+018
2E+018
Distance from surface (mm)
Ele
ctr
on
Co
nc
en
tra
tio
n
(cm
-2)
Carrier confinement
Heterojunction Homojunction
Higher optical losses
0 0.4 0.8 1.2 1.60
5E+017
1E+018
1.5E+018
2E+018
Distance from surface (mm)
Ele
ctr
on
Co
nc
en
tra
tio
n
(cm
-2)
Heterojunction Homojunction
Index profile
Intensity profile
1%
10%
1 exp Cd n n : the difference in the reflective indexd : the thickness of the active layer, C : Constant
Optical confinement
8
How Important is this Invention?
About $4B annually
Laser Focus World Jan. 2013
All commercial diode lasers use double heterostructures
Herb’s patent runs out
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…
Hybrid Silicon Ring Isolator
1551.0 1551.1 1551.2 1551.3 1551.4-60
-58
-56
-54
-52
-50
-48
-46
Tra
nsm
issi
on
(d
Bm
)
Wavelength (nm)
inward-direction magnetic field outward-direction magnetic field
Tien et al. “Silicon ring isolators with bonded nonreciprocal magneto-optic garnet” Optics Express (2011).
First experiment Optimized design