The application of magnetic fields to semiconductor lasers gives rise to significant alterations in their oscillation wavelengths. Reports dating back to the 1960's describe shifts to shorter oscillation wavelengths, at extremely low temperatures (80K) and strong magnetic fields (~4T). These shifts were explained by the effect of the Landau Level. In our preliminary experiments, we exposed bulk-type semiconductor lasers oscillating at 780nm to a relatively weak magnetic field (1.4T), at room temperature (300K), observing, in the process, that the oscillation wavelength shifted to the longer (low-frequency) side. This work looks at the longer side shift, the optical output-power shift on the low-power side, and the terminal-voltage shift seen on the higher voltage side of some multi-quantum-well (MQW) laser diodes oscillating at 780nm, under the same experimental conditions we employed in previous works. In discussions of shift mechanisms, we consider how wavelength (frequency), optical output-power, and terminal voltage-shifts are correlated. Our expanded knowledge base has forced a complete rethink of the mechanisms we relied upon in the 1960's. Current evidence suggests that the temperature rise and the longitudinal magneto-resistance effect were "co-conspirators" in the shifts observed in our experiments, when we applied magnetic fields to laser diodes parallel to the injection current. In an upcoming report, we will describe the results of experiments conducted near the threshold current.
Semiconductor lasers' oscillation wavelengths respond to temperature- and magnetic field-fluctuations. As reported in the 1960's, these wavelengths shortened, at lower than 80K, under a magnetic field larger than 4T. This phenomenon attracted our attention, during preliminary experiments, because, when we exposed bulk-type semiconductor lasers oscillating at 780nm to relatively weak magnetic fields (less than 1.4T), at room temperature (300K), we observed that the oscillation wavelength shifted to the longer (lower frequency) side. For this work, we focused on the longer oscillation wavelength shift, the lower power side optical output-power shift, and the higher voltage side terminal voltage shift of a number of multi-quantum-well (MQW) laser diodes oscillating at 780nm, under the same experimental conditions as those used in our previous works. In discussions of these shift mechanisms, we consider how wavelength (frequency), optical output-power, and terminal voltage shifts are correlated. Our expanded knowledge base has forced us to employ mechanisms completely different from those used in studies dating as far back as the 1960's. We are now introducing a mechanism in which temperature rise and the longitudinal magneto-resistance effect cause the shifts observed in our experiments.