Date of Graduation
Level of Access
Restricted: Campus/Bates Community Only Access
Bachelor of Science
Department or Program
Physics and Astronomy
Number of Pages
We study polarization dynamics of vertical-cavity surface-emitting lasers (VCSELs) subject to optical injection, optical feedback, or a combination of the two. First, dynamics of the VCSEL in single mode operation under single beam injection alone are studied for both parallel and orthogonal injection. Observed behaviors include period 1 (P1) and period 2 (P2) dynamics, polarization switching, and injection locking. The response of the VCSEL to feedback alone is also investigated in the isotropic and polarization-rotated cases. Fluctuations in each polarization of the VCSEL are analyzed through power spectrum measurements and calculations of correlation coefficients and permutation entropies. Isotropic feedback generally triggers dynamics with periods equal to the feedback delay times, while dynamics associated with the rotated feedback exhibit a doubled period. The y-polarized output power of the VCSEL was enhanced, and an anti-correlation between lasing polarizations for periods corresponding to the feedback delay time was recorded. Finally, we studied the dynamics when the VCSEL is subject to polarized injection and polarized feedback simultaneously. We observe that orthogonal injection can enhance or suppress feedback dynamics, while parallel injection is responsible for fluctuations with a higher number of discrete frequencies in the power spectrum. The polarization of the feedback does not directly influence the type of dynamics observed, but the rotated case still exhibits period-doubled fluctuations.
Components of Thesis
1 pdf file
Bigagli, Niccolo, "Polarization Dynamics induced by Optical Perturbations in Vertical-Cavity Surface-Emitting Lasers" (2017). Honors Theses. 222.
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