Simultaneous temperature and pressure sensing based on a single optical resonator.

We propose a dual-parameter sensor for the simultaneous detection of temperature and pressure based on a single packaged microbubble resonator (PMBR). The ultrahigh-quality (∼107) PMBR sensor exhibits long-term stability with the maximum wavelength shift about 0.2056 pm. Here, two resonant modes with different sensing performance are selected to implement the parallel detection of temperature and pressure. The temperature and pressure sensitivities of resonant Mode-1 are -10.59 pm/°C and 0.1059 pm/kPa, while the sensitivities of Mode-2 are -7.69 pm/°C and 0.1250 pm/kPa, respectively. By adopting a sensing matrix, the two parameters are precisely decoupled and the root mean square error of measurement are ∼ 0.12 °C and ∼ 6.48 kPa, respectively. This work promises the potential for the multi-parameters sensing in a single optical device.

Ultra-low-power all-optical switching device by use of ytterbium-doped fiber Bragg gratings.

A new, to our knowledge, scheme of all-optical switching is put forward by use of an all-fiber Mach-Zehnder interferometer incorporating ytterbium-doped fiber Bragg gratings. The device utilizes the characteristics of the sharp change of group velocity in transmission with the detuning parameter, delta = 2pi n(1/lambda - 1/lambdaB). The switching is achieved by changing the Bragg wavelength of the ytterbium-doped arm of the interferometer. A very small shift of the Bragg wavelength can lead to a pi phase shift between the two arms, so the power needed to realize complete switching is much lower than that of other schemes. In addition, the device can compensate the dispersion of an optical pulse through the positive group velocity dispersion in transmission provided by the gratings.