We report that the complex conjugate artifact in Fourier domain optical coherence tomography approaches (including spectral domain and swept source OCT) may be resolved by the use of novel interferometer designs based on 3x3 and higher order fiber couplers. Interferometers built from NxN (N>2) truly fused fiber couplers provide simultaneous access to non-complementary phase components of the co...

Insertion loss is an important parameter used to characterize passive fiber-optic components, such as WDM couplers and variable optical attenuators. This article describes an automated insertion loss measurement system which incorporates 980 nm, 1310 nm, 1529 nm and 1561 nm DFB lasers and two internal fiber optic standards. Insertion loss measurements collected with the system for WDM couplers ...

In this paper, all-optical logical gates based on mismatched nonlinear two-core fiber couplers are proposed. In these devices, solitonlike logical input pulses are shown to avoid pulse breakup to perform logical operations. The mismatched two-core fiber couplers can be produced through slightly different cores embedded in the same cladding. In this situation, the two cores have different disper...

An interferometric model is proposed to estimate the phase differences in lossless, strongly coupled biconical fiber couplers. This approximate method is simpler than the traditional s-parameter network theory-based analysis technique and minimizes the number of unknowns. The phase difference between the transmitted and coupled light fields is directly related to the field interaction and can b...

We demonstrate single-mode ZBLAN optical fiber couplers. A controlled tapering procedure leads to coupling ratios of 5%/95% and 14%/86% at a wavelength 2200 nm, with insertion losses 1.6 dB 1.8 dB, respectively.

Low current sensitivity and insufficient system stability are two key problems in all-fiber current sensor (AFCS) studies. In order to solve the two problems, a novel AFCS combining single-polarization single-mode (SPSM) couplers and a loop structure is presented in this paper with a design that incorporates the advantages of both SPSM couplers and a loop structure. SPSM couplers are shown to s...

We propose a new all fiber Mach-Zehnder-Sagnac hybrid interferometer topology for precision sensing. This configuration utilizes a high coherence laser source, mitigates the effects of Rayleigh backscatter and polarization wander, while eliminating scale factor drift. We also present preliminary experimental results, using telecommunications grade single mode fiber and fiber couplers, to demons...

Directional mode coupling in an asymmetric holey fiber coupler is demonstrated both numerically and experimentally for the first time. The holey fiber mode couplers have interesting spectral characteristics and are also found to exhibit increased dimensional tolerances. Following a design based on numerical investigations, a dual-core polymer holey fiber coupler for LP(01) and LP(11) mode multi...