timedate
Member level 5
Hi all
Does anybody know why InGaAs photodiode is always small than silicon photodiode?
For example, **broken link removed** from hamamatsu, it has diameter of 1mm, and 90pF capacitance. and cut-off frenquency is 35MHz.
while for a silicon photodiode, for example, **broken link removed**, diameter is 1.2mm, 3pF capacitance, and cut-off frenqucy is 100Mhz.
So, almost the same size, but a huge difference in Capacitance.
is it because the InGaAs has a large "permittivity" than silicon? I searched, but I could not find the the value of permittivity for InGaAs.
Does anybody know why InGaAs photodiode is always small than silicon photodiode?
For example, **broken link removed** from hamamatsu, it has diameter of 1mm, and 90pF capacitance. and cut-off frenquency is 35MHz.
while for a silicon photodiode, for example, **broken link removed**, diameter is 1.2mm, 3pF capacitance, and cut-off frenqucy is 100Mhz.
So, almost the same size, but a huge difference in Capacitance.
is it because the InGaAs has a large "permittivity" than silicon? I searched, but I could not find the the value of permittivity for InGaAs.