Status : Rejected
Personal Name Manuel, Ma. Adoracion P.
Resource Title Spectral and temporal characteristics of a 635 nm laser diode subjected to optical feedback from an Etalon
Date Issued October 2005
Abstract We investigated the spectral and temporal characteristics of a 635 nm laser diode (LD) in an external cavity consisting of an etalon. The system utilized optical feedback (OF) from the etalon which transforms the effective reflectivity of the LD cavity. The experiments were carried out at two different temperatures, T=25°C and 20°C. The characteristics of a free-running LD were obtained initially. The LD was operated at three different operating currents, Iop=60, 65 and 70 mA. The free-running spectrum for each current consists of a broad profile. It was observed that the relative intensity of the free-running LD output increases with the operating current. This behavior holds for both temperature settings. For T=25°C, the average power measured were P=456.66, 965.00 and 1635.66 μW; the FWHM were Dl=9.2, 8.2 and 8.1 Å; and the associated coherence lengths are zc=70.84,79.58 and 80.69 μm for Iop=60,65 and 70 mA, respectively. For T=20°C, the average power measured were P= 667.00, 1026.66 and 1410.00 μW; the FWHM were Dl=8.5, 8.2 and 8.4Å; and the associated coherence lengths are zc= 76.59, 79.50 and 77.70 μm for Iop=60,65 and 70 mA, respectively. The behavior of temporal coherence length was also investigated at varying reflectivity. For T=25°C, the maximum associated coherence lengths obtained at R = 0.311, 0.300 and 0.303 are zc= 673.62, 1080.62 and 785.61 μm for Iop=60, 65 and 70 mA respectively. These maximum values of temporal coherence lengths obtained all fall within the reflectivity range 0.3
Degree Course Master of Science in Physics
Language English
Keyword laser diode
Material Type Thesis/Dissertation