Operated by the Southeastern Universities Research Association for the U.S. Depart. Of Energy

Thomas Jefferson National Accelerator Facility

Strained superlattice from SVT

GaAs P1-x x , 0<x<0.36 (2.5 μm)

p-type GaAs substrate

GaAs (5 nm)

GaAs (4 nm)

GaAsP (3 nm)

GaAs P0.64 0.36 (2.5 μm)

14 pairs

5.1019

5.1017

5.1018

Be doping

Operated by the Southeastern Universities Research Association for the U.S. Depart. Of Energy

Thomas Jefferson National Accelerator Facility

Quantum Efficiency

At bandgap:

I ~ 6 muA/mW

Operated by the Southeastern Universities Research Association for the U.S. Depart. Of Energy

Thomas Jefferson National Accelerator Facility

Polarization

Pe ~ 80% at 780 nm

Operated by the Southeastern Universities Research Association for the U.S. Depart. Of Energy

Thomas Jefferson National Accelerator Facility

Analyzing power

SVT superlattice: A.P. ~ 3%

Peak to peak A.P.

Spire strained layer: A.P. ~ 10%

Operated by the Southeastern Universities Research Association for the U.S. Depart. Of Energy

Thomas Jefferson National Accelerator Facility

Conclusions

• Polarization at least as high as S.L. P ~ 80%

• QE is 5 times higher than S.L. QE ~ 1%

• Analyzing power smaller A.P. ~ 3%

• Wafer treatment different, under study

• Sample loaded in tunnel failed

Highs:

Lows:

Operated by the Southeastern Universities Research Association for the U.S. Depart. Of Energy

Thomas Jefferson National Accelerator Facility

Polarization uniformity

Uniform across a single chip