Chow, JongRabeling, DavidWade, AndrewLittler, IanGray, MalcolmMcClelland, David2015-12-13June 2-4 29781557528698http://hdl.handle.net/1885/84285We demonstrate an active cavity impedance matching control technique using radiofrequency amplitude modulation homodyne interferometry, and show it can be used for absorption spectrometry at the quantum limit for both narrow and broadband molecular transitions.Keywords: Absorption spectrometry; Active cavity; Homodynes; Impedance matching control; Impedance matchings; Molecular transitions; Quantum limit; Radio frequencies; Spectroscopic sensing; Electron optics; Impedance matching (electric); Lasers; Quantum electronics20092016-02-24