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From what I understand, there are traditional photodiode components that are designed with PIN diodes, in which the gate is activated by light saturation. For a PIN diode component made for RF switching applications, the gate is operated by applying a forward bias current.

How closely related are these two types of components? For example, if I take a photodiode and fully saturate the sensor with light, would it operate in the same fashion as an RF PIN diode? Would an RF signal be able to pass?

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Yes.

Have a look at this thesis - A picosecond optoelectronic cross correlator using a gain modulated avalanche photodiode for measuring the impulse response of tissue David Kirkby, April 1999 discovery.ucl.ac.uk/1456753/1/D_R_Kirkby_PhD_Thesis.pdf

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  • \$\begingroup\$ Thanks. I'm trying to digest the paper (250 pages!), but perhaps you are more familiar with the topic and can clarify something. In the paper, are they modulating the electrical signal before sending it into the photodiode? Or are they just using the laser pulses to induce a modulated signal that exits the photodiode? Most of the applications I've found, they're inducing the modulated signal with the laser, so I just wanted to make sure before I read this whole thing. Maybe you have a page number to reference? \$\endgroup\$
    – DannyC
    Oct 3, 2018 at 22:52
  • \$\begingroup\$ Not my thesis, but I think that they are modulating the diode with a delayed version the pulse and the optical pulse - by varying the delay a cross-correlation plot is formed and from that your can estimate of the delay caused by the optical signal propagating in the scattering media (ie tissue). It's been about 15 years since I was working on this kind of stuff - I just remembered the thesis. \$\endgroup\$
    – D Duck
    Oct 3, 2018 at 23:18
  • \$\begingroup\$ Ok great, that makes sense. The diagrams of their setup show the "correlating APD" (avalanche photodiode) as having two input signals, so this must be correct. Great memory! \$\endgroup\$
    – DannyC
    Oct 4, 2018 at 1:04

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