Cylindrical optical microcavities: Basic properties and sensor applications

Fluorescent polymer coated capillaries as optofluidic refractometric sensors

“…A method for calculating the resonant wavelengths of FCMs was discussed by Rodriguez et al [17] and the method is extended here using a complex frequency eigenvalue technique previously used for multilayer cylindrical [18,19] and thin-walled capillary resonators [20], enabling the calculation of the quality factors (Q) and radiative fields presented below.…”

“…Since the field of the fundamental m = 1 resonance decays faster as r → 0 than the m > 1 resonances, and higher order capillary modes typically have a lower Q [20], the m = 1 mode maintains a larger Q for thinner layers. Similar effects have been described for thin-walled capillaries [20].…”

Whispering Gallery Mode Devices for Sensing and Biosensing

“…Cylindrical structures can also have some component of the mode k-vector along the capillary axis; i.e., the spiraling WGMs [44]. Evidence for cylindrical spiraling modes is sometimes reported as a short-wavelength shoulder or skewing of an otherwise Lorentzian WGM mode shape [7,45,46]. The magnitude of the resonance shift as a function of spiral angle has been derived, assuming relatively small angles [44]:…”

Sensitivity of an optical sensor based on capillary microresonator for the measurement the hydrostatic pressure in microfluidics

“…These optical microresonators have been manufactured with different morphologies in the form of capillaries [1][2][3][4], discs [5], rings [6 -8], toroids [9], spheres [10], bubbles [11], bottles [12], etc, using different materials such as silicon, silica, polymers, with applications in areas such as biology [13], medicine [4], physics [14], chemistry [10] and specifically in the area of sensors for the measurement of temperature [15], humidity [12], refractive index [16] and some other physical variables of interest [6]. Specifically, the cylindrical optical microcavities that have been made using different types of materials, experience a series of resonances commonly known as Whispering Gallery modes WGMs, which are characteristic of the cavities that have rotational symmetry and can be explained through the phenomenon of total internal reflection occurring within these cavities when they are excited through an external source.…”