PURPOSE To evaluate the biomechanical changes occurring after LASIK flap creation and rapid corneal cross-linking (CXL) measured with Brillouin light microscopy. METHODS Porcine eyes (n = 11) were evaluated by Brillouin light microscopy sequentially in the following order: virgin state, after LASIK flap creation, and after rapid CXL. Each eye served as its own control. Depth profile of the Br...

A useful method for eliminating the detrimental effect of laser frequency instability on Brillouin signals by employing the self-heterodyne detection of Rayleigh and Brillouin scattering is presented. From the analysis of Brillouin scattering spectra from fibers with different lengths measured by heterodyne detection, the maximum usable pulse width immune to laser frequency instability is obtai...

The magnetic properties of intact and freeze-dried blood cells of the tunicate Ascidia nigra and of model vanadium(III) and (IV) compounds as polycrystalline solids and in aqueous solution have been measured up to 50 kOe with a SQUID susceptometer. Corrections for the samples' diamagnetism were extracted from the temperature dependence of the data without any further assumptions. For vanadium(I...

Although bolometricand ponderomotive-induced deflection of device boundaries are widely used for laser cooling, the electrostrictive Brillouin scattering of light from sound was considered an acousto-optical amplification-only process1–7. It was suggested that cooling could be possible in multiresonance Brillouin systems5–8 when phonons experience lower damping than light8. However, this regime...

Stimulated Brillouin Scattering (SBS) is one of the nonlinear process that can occur in optical fiber if the input power at low level [1,2]. It is a natural scattering process associate to the propagation of light in a medium. Due to the interaction of light with the propagation medium, different scattering components are generated: Rayleigh, Brillouin and Raman component. The resulting scatter...

A hybrid technique for real-time direct detection of strain and temperature along a single-mode fiber is proposed. The temperature is directly detected from the Raman backscattering in the time domain. To retrieve the strain profile from the Brillouin backscattering, an edge technique is introduced and a response function of the Fabry-Perot interferometer for the Brillouin backscattering is def...

The temperature dependence of the elastic functions of the improper ferroelastic polytype 2 MC-SbsOTI has been investigated in the temperature range from room temperature to well above the structural phase transition at T~=481 K. The stiffnesses c(c*c*), c(a,a), c22 and c(c*a) show a considerable softening up to 20% around Tc whereas c44 remains unaffected by the phase transition. The experimen...

Distributed curvature and shape sensing using Brillouin scattering in multi-core fiber (MCF) is presented for the first time to the best of our knowledge, by exploiting bend-dependent Brillouin frequency shift (BFS) in off-center cores. OCIS codes: (060.2310) Fiber optics; (290.5830) Scattering, Brillouin; (060.2370) Fiber optics sensors.

We present extensive stimulated Brillouin scattering (SBS) results from experiments and modeling for four different photonic crystal fibers (PCFs) with core diameters ranging from 8 to 1.7 m. These results reveal several SBS characteristic features of small-core PCFs, high thresholds, and acoustic peaks, which are due to their antiguiding nature and highly multimode acoustic character. The natu...

A new scheme for distributed Brillouin sensing of strain and temperature in optical fibers is proposed, analyzed and demonstrated experimentally. The technique combines between time-domain and correlation-domain analysis. Both Brillouin pump and signal waves are repeatedly co-modulated by a relatively short, high-rate phase sequence, which introduces Brillouin interactions in a large number of ...