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Quantum technologies

Dieter Meschede's research group
Home Group members Pooja Malik
Group members
B. Sc. Pooja Malik
Last position
in our group:
Master student
Field of research
in our group:
Fibre cavity QED

Publications(up to 2020)

  • P. Malik
    Linewidth-reduced DBR Laser for Raman Sideband Cooling, (2020), Master thesisBibTeXPDF

    In this thesis, I present how the Lorentzian linewidth of a DBR laser was reduced by implementing an external optical feedback path. Chapter 2 deals with the theoretical framework of effects of the external optical feedback on semiconductor laser and regimes of feedback in distributed feedback lasers. To measure and quantify the linewidth of the DBR laser subject to controlled optical feedback, a delayed-self heterodyne (DSH) measurement was setup and is described in Chapter 3. DBR lasers are affected not only by white frequency noise but also low-frequency flicker and random walk noise. These noise components restrict the analysis of the DSH spectrum analytically, hence a simulation based fitting routine based on is used. A comprehensive analysis of the Lorentzian linewidth is presented. An estimate on the linewidth arising from the flicker and random-walk frequency noise is also presented in this thesis. With this improvement to the DBR laser, I present in Chapter 4, the implementation of carrier-free Raman sideband cooling in the main experiment.

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