1. A semiconductor diode laser has a peak emission wavelength of 1.55 μm. Find its band gap in eV.
Sol: Energy gap of semiconductor, Eg = energy of emitted photon, hν
where c = velocity of light = 3 × 108 m/s
Wavelength, λ = 1.55 μm = 1.55 × 16-6 m
Energy gap, Eg = ?
2. Calculate the wavelength of emitted radiation from GaAs which has a band gap of 1.44 eV.
Sol: Energy gap of semiconductor, Eg = hν
h = Planck’s constant = 6.63 × 10-34 J-S