Balanced detection technique to measure small changes in transmission.
A novel technique to measure changes in optical transmission of better than 10(-3) with time resolution of better than 10 ns is discussed. The photocurrent from two photodiodes is subtracted with a balanced detection circuit to eliminate the common signal; carrier-induced change in absorption for a semiconductor single quantum well produces a large differential signal.
Houser
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GD
Garmire
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E