For the "photons per bit" question, the useful throughput of 140 bps is the only thing that matters. For the "how many photons are needed" question, I agree th

For the "photons per bit" question, the useful throughput of 140 bps is the only thing that matters. For the "how many photons are needed" question, I agree that 320 baud (i.e., the effective analog bandwidth of 320 Hz) should have been used for the Shannon-Hartley calculations.