| 摘要 |
PURPOSE: To effectively obtain TE and TM polarized wave oscillation ranges by providing a phase shifter in one region, and differentiating an α parameter to the TE and TM waves. CONSTITUTION: Since TE and TM polarized waves have different effective refractive indexes (n), Bragg's wavelengths λ are different, and the wavelength difference is about 4nm. The relationship between the injection carrier density N and a gain (g) is such that, when the wavelengths are different, the value of dg/dN is different and the parameters are different (α parameter :4π/λ.(dn/ dN)/(dg/dN)). The relationship between the threshold currents of the two electrodes of the TE polarized wave is asymmetrical with respect to a straight line of 11 =12 since a λ/4 phase shifter 21a is provided only at the region of one electrode. Since the TM wave is different at the dg/dN from the TE wave, the threshold currents of the two electrodes are different. As a result, the lower one of the threshold currents of the TE and TM waves is easily oscillated. Since the two curves are crossed, oscillating regions of the TE and TM waves are generated, and both the regions can be effectively obtained. |
