Electrostrictive optical resonators for non-contact displacement measurement.

This paper describes a non-contact transduction mechanism for the measurement of linear displacements that is based on the electrostrictive properties of a polymeric optical resonator. The spherical resonators, with a diameter of ∼1  mm and an average optical quality factor of ∼10, are made using a commercially available polymer (Super Soft Plastic-Manufacturing Company). The spherical resonator is immersed in a homogeneous electric field that is generated by applying a voltage difference between two metallic plates.

Untethered photonic sensor for wall pressure measurement.

In this Letter, we study a novel untethered photonic wall pressure sensor that uses as sensing element a dome-shaped micro-scale laser. Since the sensor does not require any optical or electrical cabling, it allows measurements where cabling tends to be problematic. The micro-laser is made by a mixture of Trimethylolpropane Tri(3-mercaptopropionate), commercial name THIOCURE and Polyethylene (glycol) Diacrylate (PEGDA) mixed with a solution of rhodamine 6G.

Effect of wall pressure and shear stress on embedded cylindrical microlasers.

In this paper, we carried out numerical experiments to study the effect of the shear stress and the wall pressure on the optical mode shift of two embedded cylindrical microlasers. The optical cavities (laser) are encapsulated in a slab that is clamped at the bottom surface while the other sides of the slab are free-stress boundaries. When a uniform shear stress and pressure is applied on the top surfaces of the slab, the morphology of the optical resonators are perturbed.

High data rate transient sensing using dielectric micro-resonator.

An approach to high-speed tracking of optical mode shifts of microresonators for wide-bandwidth sensing applications is presented. In the typical microresonator sensor, the whispering gallery optical modes (WGM) are excited by tangentially coupling tunable laser light into the resonator cavity, such as a microsphere. The light coupling is achieved by overlapping the evanescent field of the cavity with that of a prism or the tapered section of a single-mode optical fiber.

Dome-shaped whispering gallery mode laser for remote wall temperature sensing.

In this paper, we carried out experiments to investigate dome-shaped microlaser based on the whispering gallery modes for remote wall temperature sensing. The dome-shaped resonator was made of Norland blocking adhesive (NBA 107) doped with a solution of rhodamine 6G and ethanol. Two different configurations are considered: (i) resonator placed on top of a thin layer of 10:1 polydimethylsiloxane (10:1 PDMS), and (ii) resonator encapsulated in a thin layer of 10:1 PDMS.

Effect of angular velocity on sensors based on morphology dependent resonances.

We carried out an analysis to investigate the morphology dependent optical resonances shift (MDR) of a rotating spherical resonator. The spinning resonator experiences an elastic deformation due to the centrifugal force acting on it, leading to a shift in its MDR. Experiments are also carried out to demonstrate the MDR shifts of a spinning polydimethylsiloxane (PDMS) microsphere.

Development of whispering gallery mode polymeric micro-optical electric field sensors.

Optical modes of dielectric micro-cavities have received significant attention in recent years for their potential in a broad range of applications. The optical modes are frequently referred to as "whispering gallery modes" (WGM) or "morphology dependent resonances" (MDR) and exhibit high optical quality factors. Some proposed applications of micro-cavity optical resonators are in spectroscopy, micro-cavity laser technology, optical communications as well as sensor technology.

Magnetorheological polydimethylsiloxane micro-optical resonator.

We investigate the possibility of using magnetorheological polydimethylsiloxane (MR-PDMS) spheres as micro-optical resonators. In particular, the effect of a magnetic field on the whispering gallery modes (WGM) of these resonators is studied. The applied field induces mechanical deformation, causing shifts in the WGM.

Tuning of whispering gallery modes of spherical resonators using an external electric field.

In this paper we investigate the electrostriction effect on the whispering gallery modes (WGM) of polymeric microspheres and the feasibility of a WGM-based microsensor for electric field measurement. The electrostriction is the elastic deformation (strain) of a dielectric material under the force exerted by an electrostatic field. The deformation is accompanied by mechanical stress which perturbs the refractive index distribution in the sphere.

Micro-optical force sensor concept based on whispering gallery mode resonators.

A micro-optical force sensor concept based on the morphology-dependent shifts of optical modes of dielectric microspheres is investigated. The optical resonances, commonly referred to as the whispering gallery modes (WGM), were excited by evanescently coupling light from a tunable diode laser using a tapered single-mode fiber. A compressive force applied to the sphere induces a change in both the shape and the index of refraction of the sphere leading to a shift in WGM.