Standing-wave Fourier transform interferometer with an HPT

A compact standing-wave Fourier transform interferometer is experimentally demonstrated in a very broad band. By using an InP-InGaAs-InAlAs heterojunction bipolar phototransistor (HPT) and a PZT-controlled scan mirror, a resolution of 37.5cm/sup -1/ was achieved with a mirror travel length of only 32μm at the fifth harmonic order spectrum component. The experimental results agree well with the mathematical models, and the interferometer resolution could be further improved.