Longitudinal modes evolution of a GaN-based blue laser diode

Impact of Mode-Hopping Noise on InGaN Edge Emitting Laser Relative Intensity Noise Properties

“…We measure for the gain and the clusters shifts of 23.9 pm/mA and 7.5 pm/mA, respectively. The related ratio of 3.2 is comparable to previously reported values [25], [28]. A ratio larger than one allows adjacent clusters to lase for some pump current values since the gain curve redshifts faster than the clusters do.…”

“…This phenomenon is at the origin of the laser swinging between single and bicluster operation. Second, a tiny variation in the refractive index due to a change in the carrier density will also redshift the clusters [28]. These two effects contribute to the redshift of the lasing wavelengths with two specific slopes.…”

Littrow configuration tunable external cavity diode laser with narrowband emission at 448 nm

“…[9] Regarding laser diodes that may be suitable for the application, Fabry-Perot (FP) laser diodes, which are the cheapest and most common type of laser diode, are generally not suitable for direct use in high-resolution spectroscopic measurements due to their broadband emission spectrum of several nanometer (multi-longitudinal mode emission). [10] To overcome this limitation, single-mode laser diodes with narrow-band emission and having a monolithically incorporated optical feedback structure for mode selection may be the solution. In fact, to the best of our knowledge, DFB, DBR laser diodes, as well as VCSEL, are not commercially available in the blue spectral region coinciding with the strong absorption cross-section of NO 2 gas molecule.…”