Thermal tuning of a fiber-integrated Fabry-Pérot cavity

Abstract

Here, we present the thermal tuning capability of an alignment-free, fiber-integrated Fabry-Pérot cavity. The two mirrors are made of fiber Bragg gratings that can be individually temperature stabilized and tuned. We show the temperature tuning of the resonance wavelength of the cavity without any degradation of the finesse and the tuning of the individual stop bands of the fiber Bragg gratings. This not only permits for the cavity’s finesse to be optimized post-fabrication but also makes this cavity applicable as a narrowband filter with a FWHM spectral width of 0.07 ± 0.02 pm and a suppression of more than -15 dB that can be wavelength tuned. Further, in the field of quantum optics, where strong light-matter interactions are desirable, quantum emitters can be coupled to such a cavity and the cavity effect can be reversibly omitted and re-established. This is particularly useful when working with solid-state quantum emitters where such a reference measurement is often not possible once an emitter has been permanently deposited inside a cavity.

Short-Pulse Photothermal Modulation of Silicon Optical Cavities Measured by a Continuous Mid-IR Probe

“…These effects give rise to applications such as photothermal detection of light, , photoacoustic spectroscopy, − photothermal calorimetry, − and photothermal therapy. − An important recent example is photothermal microscopy, − where subdiffraction IR microscopy has been made possible by detecting photothermal expansion of the IR-absorbing regions in a sample using visible light. Optical cavities are susceptible to thermal effects due to either expansion or refractive index change. , They are essential components in a wide range of applications spanning thin-film interference filters, lasers, and cavity-enhanced spectroscopy. , Therefore, photothermal control of optical cavities is technologically relevant and promising.…”

“…Optical cavities are susceptible to thermal effects due to either expansion or refractive index change. 15,16 They are essential components in a wide range of applications spanning thin-film interference filters, 17 lasers, and cavity-enhanced spectroscopy. 18,19 Therefore, photothermal control of optical cavities is technologically relevant and promising.…”