Numerical Investigation into Optoelectronic Performance of InGaN Blue Laser in Polar, Non-Polar and Semipolar Crystal Orientation

Recently, InGaN grown on semipolar and non-polar orientation has caused special attraction due to reduction in the built-in polarization field and increased confinement of high energy states compared to traditional polar c-plane orientation. However, any widespread-accepted report on output power and frequency response of the InGaN blue laser in non-c-plane orientation is readily unavailable. This work strives to address an exhaustive numerical investigation into the optoelectronic performance and frequency response of In_0.17Ga_0.83N/GaN quantum well laser in polar (0001), non-polar (101̅0) and semipolar (101̅2), (112̅2) and (101̅1) orientations by working out a 6 × 6 k.p Hamiltonian at the Γ-point using the tensor rotation technique. It is noticed that there is a considerable dependency of the piezoelectric field, energy band gap, peak optical gain, differential gain and output power on the modification in crystal orientation. Topmost optical gain of 4367 cm⁻¹ is evaluated in the semipolar (112̅2)-oriented laser system at an emission wavelength of 448 nm when the injection carrier density is 3.7 × 10¹⁸ cm⁻³. Highest lasing power and lowest threshold current are reported to be 4.08 mW and 1.45 mA in semipolar (112̅2) crystal orientation. A state-space model is formed in order to achieve the frequency response which indicates the highest magnitude (dB) response in semipolar (112̅2) crystal orientation.