Any single photon detector within the telecommunications range (1550 nm) will be ok. I am involved in a project for data and massage encryption. Phase modulation of the data carrying single photon light is used for encryption. For phase modulation a crystal will be used which obeys Pockels effect (birefringence is proportional to the applied electric field) and single photon will be released by a laser diode. So far a laser diode has been assembled, and we are still looking for chipper retailers which cut (up to nano size) and sell crystals. Conclusively the system will have laser diode (massage), optical phase modulator (for massage encryption) and single photon detector (to read the encrypted massage)