A photo detector can include: a light emitting device configured to emit light a driving circuit configured to drive the light emitting device a photo-electric conversion circuit configured to generate an optical current signal according to an optical signal an isolation circuit configured to transmit the optical current signal in an isolated manner an ambient light filter configured to filter a current component of the optical current signal corresponding to an ambient light, and to generate a clean optical current signal a current amplification circuit configured to amplify the clean optical current signal, and to generate an amplified optical current signal (vii) an analog-to-digital converter configured to convert the amplified optical current signal to a digital signal and a control circuit configured to output an optical detection signal according to the digital signal.
