Quantum efficiency of a photodiode (ratio between the number of liberated electrons and the number of incident photons) is $0.75$ at $830\;nm$. Given Planck’s constant $h=6.624\times10^{-34}J$, the charge of an electron $e=1.6\times10^{-19}C$ and the velocity of light in the photodiode $C_m=2\times10^8\;m/s$. For an incident optical power of $100 \;\mu W$ at $\text{830 nm}$, the photocurrent in $\mu A$ is ________________ .