1. Current Channeling – End View, Vertical Section, Not to scale
p-Type Electrode
p-GaAs Cap Layer
n-GaAs Current Blocking Layer
p-AlGaAs Cladding Layer
AlGaAs Active Layer
Laser Mode Volume
n-AlGaAs Cladding Layer
p-GaAs Current Blocking Layer
n-GaAs Buffer Layer
Path of Current Flow
Substrate Z Y
n-Type Electrode

2. Gain Increase and Longitudinal Mode Stabilization of Semiconductor Lasers by means of Current Channeling
n-GaAs Current Blocking Layer
Channeled Current
P-GaAs Cap Layer
p-AlGaAs Cladding Layer
p-Type Electrode
Maximum Overlap of Current and Antinode of Standing Wave
X-Y Section
Laser Emission
Standing Wave
AlGaAs Active Layer
n-GaAs Buffer Layer Z X Y
n-GaAs Substrate
(Y-direction normal to screen)
n-Type Electrode
n-Type Electrode
Y-Z Section
p-GaAs Current Blocking Layer
n-AlGaAs Cladding Layer

3. Schematic of Current Channeling – Top View (not to scale)
X-Y Section
n-GaAs Current Blocking Layer
~50nm
~0.25mm Y X
Current Path Spacing < ~l/4
n-GaAs Current Blocking Layer Spacing = ~l/2
Current Path is Between Blocking Layers
Laser Mode Volume

4. Schematic of Current Channeling – Y-Z Section Approximately to Scale
~0.5mm
Entire Active Region is ~100nm
~0.5mm Z Y
Substrate
Note: Because of the extreme thinness of the active region, it is not possible to show the entire device to scale

5. Schematic of Current Channeling in Phased Array Diode Laser– Top View (not to scale) X-Y Section
~0.5mm
~0.25mm Y X
Emitter “stripe”
End View
n-GaAs Current Blocking Layers Spacing = ~l/2; Current Path Spacing < ~l/4 Z Y