Femtosecond Transient Imaging

MIT: Femtosecond Transient Imaging

Looking around the corner using transient imaging

Birefringence

The resolution or splitting of a light wave into two unequally reflected or transmitted waves by an optically anisotropic medium such as calcite or quartz. Also called double refraction. [Answers.com]

Crystalline materials may have different refractive index (n) associated with different crystallographic directions. A common situation with mineral crystals is that there are two distinct n, and they are called birefringent materials. If the y- and z- directions are equivalent in terms of the crystalline forces, then the x-axis is unique and is called the optic axis of the material.

The propagation of light along the optic axis would be independent of its polarization; it’s electric field is everywhere perpendicular to the optic axis and it is called the ordinary- or o-wave.

The light wave with E-field parallel to the optic axis is called the extraordinary- or e-wave. Birefringent materials are used widely in optics to produce polarising prisms and retarder plates such as the quater wave plate. Putting a birefringent material between crossed polarisers can give rise to interference colours.

A widely used birefringent material is calcite. Its birefringence is extremely large, with indices of refraction for the o- and e-rays of 1.6584 and 1.4864 respectively. [http://hyperphysics.phy-astr.gsu.edu]

Beat Length

A characteristic of optical fibre used to calculate the fibre’s ability to maintain polarisation. The beat length describes the length required for the polarisation to rotate 2 pi. For a given wavelength, it is inversely proportional to the fibre’s birefringence.

GeAsSe and AsSe all solid MOF

GeAsSe and AsSe all solid MOFs were fabricated by researcher (Zheng gang Lian)at the University of Nottingham. The fabrication procedures involved glass melting, casting, co-extrusion, stacking and fibre draw.

The paper was published at IEEE PTL. Optical guiding was demonstrated but the optical loss did not mentioned in the paper.

http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=05272506

 

As-S suspended core MOFs

Researchers at ICB lab in France fabricated low loss As-S suspended core MOFs and demonstrate IR spectral broadening.

The paper published on 1/Mar/2010 on Optics Express. The optical loss of the fibre is ~ 0.35dB/m at 1.55 micron meter wavelength (2.3 micron meter core diameter).  The high nonlinear chalcogenide glass MOF can be used for light conversion in the MIR region

Useful simulation tools for planar waveguides and fibers:

Useful simulation tools for planar waveguides and fibers:

FIMMWAVE  (Photon design) http://www.photond.com/products/fimmwave.htm

Optiwave http://www.optiwave.com/

Rsoft http://www.rsoftdesign.com/

Lumerical http://www.lumerical.com/

EMFlex http://www.wai.com/emflex.aspx

FreeBPM http://www.freebpm.com/

SMU Waveguide http://lyle.smu.edu/ee/smuphotonics/WAVEGUIDE/Main_Waveguide.htm

MIT Photonic-Bands (MIT) http://ab-initio.mit.edu/wiki/index.php/MIT_Photonic_Bands

Comsol http://www.comsol.com/industry/application/rf/po/

SMTP v2.0 (The source-model technique package) http://webee.technion.ac.il/leviatan/smtp/index.htm

Reference:

http://www.nusod.org/inst/software.html