Selective wavelength conversion in a few-mode fiber.

We experimentally demonstrate a means to selectively enhance wavelength conversion of WDM channels on a 100 GHz grid exploiting nonlinear effects between the spatial modes of a few mode fiber. The selectivity of parametric gain is obtained by dispersion design of the fiber such that the inverse group velocity curves of the participating modes are parallel and their dispersion is suitably large. We describe both theoretically and experimentally the observed dependence of the idler gain profile on pump mode (quasi) degeneracy.

Optimal fiber design for large capacity long haul coherent transmission [Invited].

Fiber figure of merit (FOM), derived from the GN-model theory and validated by several experiments, can predict improvement in OSNR or transmission distance using advanced fibers. We review the FOM theory and present design results of optimal fiber for large capacity long haul transmission, showing variation in design results according to system configuration.

1.7-µm spectroscopic spectral-domain optical coherence tomography for imaging lipid distribution within blood vessel.

We have developed a spectroscopic optical coherence tomography (OCT) for imaging lipid distribution within blood vessel in order to detect coronary artery plaque. A 1.7-µm spectral-domain OCT with A-scan rate of 47 kHz is fabricated using a broadband light source based on super-luminescent diodes and spectrometers based on extended InGaAs line sensors. We demonstrate imaging of lipid distribution in an in vitro artery model with lipid. The sensitivity and specificity in the differentiation between artery and lipid are 87% and 90% in the training, respectively. The validation test also shows detection of lipid with an accuracy over 90%.