At what wavelength is the photodiode operating?

Calculate the incident optical power required to operate photo current of 2.5 µA when the photodiode is operating as above.

Mumbai University > Electronics and telecommunication > Sem 7 > optical communication and networks

Marks: 10

Years: MAY 2014

Given: $ η=65\%=0.65$

$E_p=1.5× 10^{-19}J \\ I_p= 2.5 µA $

To find: Operating wavelength λ

Incident optical power $P_{in}$

Solution:

$R =\dfrac { ɳqλ}{hc} \\ hν = E_p \space and\space ν= \dfrac cλ \\ λ= \dfrac { hc}{E_p} = \dfrac {6.62× 10^{-34}∙3×10^8}{1.5 ×10^{-19}}=0.21µm \\ ∴λ=1.324 µm \\ R = \dfrac {ɳq}{hν} = \dfrac {ɳq}{E_p} = \dfrac {0.65 × 1.6× 10^{-19}}{1.5×10^{-19} }= 0.69 \\ ∴R=0.69 \\ R = \dfrac {I_p}{P_{in}} = \dfrac {2.5×10^{-6}}{P_{in}} =0.69 \\ ∴P_{in} =3.6µW$