Effects of 2 MeV proton irradiation on operating wavelength and leakage current of vertical cavity surface emitting lasers

We investigate the effect of 2 MeV proton radiation on high-speed oxide-confined vertical cavity surface emitting lasers. Fluences in the range of φ=2.5×10¹² p/cm² to φ=5×10¹⁴ p/cm² were studied and laser threshold current was found to degrade linearly with fluence according to a damage factor of K_I=2.77×10^-15cm²/p. Laser operating wavelength increased with fluence and experienced a maximum Δλ/λ of ∼0.71% at φ=5×10¹⁴ p/cm². Leakage current also increases as a result of the proton irradiation. We propose a degradation model based on mobility reduction and carrier removal.