Advanced Fiber Optics: Concepts and Technology

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

We report coupled VCSEL arrays, emitting at 1.3μm wavelength, in which both the optical gain/loss and refractive index distributions were defined on different vertical layers. The arrays were electrically pumped through a patterned tunnel junction, whereas the array pixels were realized by intra-cavity patterning using sub-wavelength air gaps. Stable oscillations in coupled modes were evidenced for 2x2 array structures, from threshold current up to thermal roll-over, using spectrally resolved field pattern

We have used distributed Raman amplification to extend the measurement distance of a Brillouin Optical Time-Domain Analysis (BOTDA) sensor. We successfully demonstrate a dynamic range of 75 km with 2 meter spatial resolution.

Development of standards and guidelines for performance specifications and testing for fibre optic sensors has been discussed since the mid-nineties of the last century in the scientific community as well as in the industry. Very global standards for the use of fibre optic components in data communication and telecommunication have been available for more than 20 years. Guidelines or substantial standards for fibre optic sensors are rather an exception. The first standard draft on generic specification of f

We experimentally investigate the effect of residual disorder on the dispersion curve of light near a band edge. A Fourier space imaging technique accurately distinguishes the propagating regime from diffusive transport and evanescent regime in planar photonic crystal. We highlight and quantify the impact of the disorder on the group velocity near a band edge. We stress that the achievement and determination of group indexes larger than 100 requires not only state of the art processing but also accurate tec

A simple physical description of the nonlinear optical interaction based on Brillouin echoes is presented. This technique makes potentially possible distributed Brillouin sensing down to centimeter spatial resolution while preserving the narrowband feature of the natural Brillouin gain spectrum. Experimental conditions for the generation of Brillouin echoes are described and demonstrations of distributed measurements using a 1 ns (10 cm) pulse are presented.

Digital holographic microscopes using two orthogonal polarized reference waves provides real-time polariscopes. Birefringence induced by internal stress is imaged in optical fibers and in fused silica substrates, where lines are written with low-energy femtosecond pulses.

In optics, optical elements are used to transform, to filter or to process physical wavefronts in order to magnify images, compensate for aberration or to suppress unwanted diffracted order for example. Because digital holography provides numerical wavefronts, we developed a digital optics, involving numerical elements such as numerical lenses and pinholes, to mimic numerically what is usually done physically, with the advantage to be able to define any shape for these elements and to place them everywhere

Femtosecond laser irradiation has various noticeable effects on fused silica. It can locally increase the index of refraction and modify the material chemical selectivity. Regions that have been exposed to the laser are etched hundred fold faster than unexposed regions. These effects are of practical importance from an application point-of-view and open new opportunities for the development of integrated photonics devices that combine structural and optical functions. Various observations reported in the li

In this paper, we present a modified transmission digital holographic microscope that can be used to image the state of polarization. The resulting device, called polarization digital holographic microscope (Pol-DHM), records in off-axis geometry the interference between two orthogonally polarized reference waves and the object wave transmitted by a microscopic sample and magnified by a microscope objective. A CCD camera records the resulting hologram. Using a single hologram, we reconstruct separately the

We describe a new method for performing simultaneous position-resolved measurements of chromatic dispersion and Brillouin shift along single-mode optical fibers. The technique provides consistent high-resolution and low-noise results for both quantities. Our measurements indicate a certain correlation between both magnitudes, although the degree of correlation varies for the different manufacturers tested.

We present a new technique for simultaneous measurement of chromatic dispersion and Brillouin shift distribution along conventional, single-mode optical fibers used in telecommunications. It is based on performing Brillouin Optical Time Domain Analysis (BOTDA) over the four-wave mixing generated by two low-power pumps ( less than or equal 10 mW). Unlike others, this technique can measure any arbitrary value of dispersion. With the use of this technique we have obtained consistent, high-resolution and low-no

Two-dimensional (2D) photonic crystals (PhCs) at near-infrared wavelengths are promising candidates for novel integrated optics applications. The main focus being on 'all PhC' monolithically integrated optical circuits. Because of well established fabrication technologies particular emphasis is on 'quasi' 2D PhCs where a 2D lattice of air holes is etched through a planar step-index waveguide providing the optical confinement in the third dimension. This approach has been successfully demonstrated both in Ga

Advanced Fiber Optics: Concepts and Technology

Chat with Graph Search

Intra-cavity patterning for mode control in 1.3μm coupled VCSEL arrays

Distributed Brillouin Fiber Sensor Featuring 2 Meter Resolution and 75 Km Dynamic Range

Guideline for Use of Fibre Optic Sensors

Light Transport and Limits of Slow Light in Real Photonic Crystal Structures in the Presence of Residual Disorder

Distributed fiber sensing using Brillouin echoes

Real-Time Birefringence Measurement with Digital Holographic Microscopy

A complete digital optics applied to digital holographic microscopy: Application to chromatic aberration compensation

Investigation of Femtosecond Laser Irradiation on Fused Silica

Birefringence measurement by use of digital holographic microscopy: examples with fiber optics and concrete samples

Simultaneous position-resolved mapping of chromatic dispersion and Brillouin shift along single-mode optical fibers

Spatially resolved measurement of chromatic dispersion and Brillouin shift along single-mode optical fibers

Experimental and numerical investigation of two-dimensional photonic crystals for application in integrated optics