1. Incident light with an energy of hv>Eg excites an electron and causes it to jump from the valence band to the conduction band, thereby creating an electron-hole (e-h) pair. Chapter 7 Optical detectors

2. An incident photon can cause the production of e-h pairs in three different regions (A, B and C) in the p-n diode. However, rapid detection is only achievable in B, the depletion region.

3. Schematic description of field strength variations in a p-n diode. Reverse voltage and external load applied.

4. By applying an intrinsic layer between the p- and n-layers, the absorption region obtained is much broader than that of a p-n diode.

5. The three layers of a front-illuminated PIN diode.

6. PIN diode for longer wavelengths. Semiconductor materials: InP and InGaAsP.

7. A high reverse voltage of 100-300 V gives the electrons such high kinetic energy that multiplication of e-h pairs occurs through collision ionization.

8. Example of the distribution of field strength in an APD among the different layers.

9. Construction of an RAPD.

10. The responsivity of a photodiode is dependent both on the wavelength of the incident light and the materials used.

11. Model of a PIN diode with internal resistance Ri, internal capacitance Ci, and external load RL.

12. Relationship between BER and optical SNR.