Manipulating the quantum state of light using on-chip microcavities
Nanophotonics for quantum computing and precision measurements
![]() | |
Author(s): |
Laís Fujii dos Santos
Total Authors: 1
|
Document type: | Master's Dissertation |
Press: | Campinas, SP. |
Institution: | Universidade Estadual de Campinas (UNICAMP). Instituto de Física Gleb Wataghin |
Defense date: | 2018-04-27 |
Examining board members: |
Gustavo Silva Wiederhecker;
Cid Bartolomeu de Araujo;
Flávio Caldas da Cruz
|
Advisor: | Gustavo Silva Wiederhecker; Thiago Pedro Mayer Alegre |
Abstract | |
Frequency comb generation has been a very active research field, with applications ranging from frequency metrology to astronomy and precise distance measurement. One of the main methods of comb generation is through cascaded four wave mixing, a third order nonlinear process in which a pair of photons is replaced by another pair with shifted frequencies while conserving energy and momentum. The high optical intensity needed to trigger the process is achieved by confining the light to a microcavity, thus reducing the power consumption by the resonant enhancement of the internal electromagnetic field. Besides the scalability potential and the energetic advantages, this microcavity-based platform enables the customization of comb parameters: the repetition rate scales with the inverse of the cavity radius as the generated sidebands should match the harmonic frequencies of the device. Also, the bandwidth is limited by the change in the free spectral range with frequency, which could be set to near zero values by carefully designing the geometry of the optical device. In the present dissertation, we study how the modal dispersion is affected by a change in the geometrical features of a silicon oxide wedge microdisk. To that end, we developed the expertise to control the wedge angle of the fabricated devices and to measure the dispersion of the fundamental mode from their transmission spectra. The results (corroborated by numerical simulations) show that the dispersion (at 1550 nm) goes from normal to anomalous as the wedge angle is increased. Furthermore, we used the fabricated devices to generate frequency combs in the anomalous dispersion regime, and concluded that the formation dynamics is well described by the modal expansion formalism (AU) | |
FAPESP's process: | 16/05038-4 - Frequency comb generation in optical microcavities |
Grantee: | Laís Fujii dos Santos |
Support Opportunities: | Scholarships in Brazil - Master |