Polarisation dependence of two-photon absorption generated by band-limited amplified spontaneous emission noise in silicon avalanche photodiodes

Two-photon absorption (TPA) generated by unpolarised band-limited amplified spontaneous emission (BL-ASE) noise is found to be within 5% of that generated by circularly polarised BL-ASE noise for silicon-based devices. A simple formula that describes the TPA generated by partially polarised BL-ASE noise as a function of material dichroism is given and verified experimentally.