Monolithic wavelength-flattened 1 x 7 single-mode fused fiber couplers: theory, fabrication, and analysis

Fabrication of 4 × 1 signal combiner for high-power lasers using hydrofluoric acid

We report a new method to fabricate a 4 × 1 signal combiner that comprises an output fiber port and a tapered fused bundle (TFB) with four input fiber ports. The TFB is etched in a solution of hydrofluoric acid and spliced with an output fiber of core diameter 105 μm and cladding diameter 125 μm. Each cladding of the four input optical fiber is etched to approximately 72.5 μm. The etched TFB was fabricated by tapering after forming a bundle of four etched optical fibers. Subsequently, the 4 × 1 signal combiner is fabricated by fusion splicing between the fabricated TFB and output optical fiber with a numerical aperture of 0.15. The efficiency of each port of the fabricated 4 × 1 signal combiner is in the range of 93.3-98.3%. When an optical power of approximately 624.5 W was input to the signal combiner, the maximum output was ~612 W and the efficiency was ~98%. The beam quality factor, M 2is measured to be approximately 14.6, which is calculated as the beam parameter product (BPP) of 5.02 mm·mrad.

Design and fabrication of a low-loss and asymmetric 1 × 5 arbitrary optical power splitter

In this paper, a low-loss and wavelength-insensitive asymmetric 1×5 arbitrary optical power splitter is designed and optimized, which is composed of a three-branch and two Y-branch elements. A low-loss and wavelength-independent arbitrary 1×5 optical power splitter can be obtained. Asymmetric 1×5 optical power splitters of different output ratios are fabricated using silica-based planar lightwave circuit (PLC) technology on a 6-inch quartz substrate. The measured results show that the IL_output1, IL_output2∼5, UNIF_output2∼5, PDL, and WDL of the output ratio 33%:67%, 50%:50%, and 95%:5% are less than (5.302 dB, 8.483 dB, 0.422 dB, 0.191 dB, 0.345 dB), (3.46 dB, 9.71 dB, 0.28 dB, 0.119 dB, 0.231 dB), and (1.52 dB, 14.15 dB, 0.44 dB, 0.366 dB, 0.561 dB), respectively, in the wavelength of 1.27 μm, 1.31 μm, 1.49 μm, 1.55 μm, and 1.625 μm.

Multimode fiber devices with single-mode performance

A taper transition can couple light between a multimode fiber and several single-mode fibers. If the number of single-mode fibers matches the number of spatial modes in the multimode fiber, the transition can have low loss in both directions. This enables the high performance of single-mode fiber devices to be attained in multimode fibers. We report an experimental proof of concept by using photonic crystal fiber techniques to make the transitions, demonstrating a multimode fiber filter with the transmission spectrum of a single-mode fiber grating.

Generation of near-field hexagonal array illumination with a phase grating

A hexagonal array not only is a nature-preferred pattern but also is widely used in optoelectronical materials and devices. We report a simple method of hexagonal array illumination based on the Talbot effect that has a theoretical efficiency of 100%. An experimental efficiency of 90.6% with a binary phase (0, pi) hexagonal grating is given. This method should be highly interesting for applications of hexagonal array illumination in optical devices as well as in other hexagonal cells.

Multidimensional solitons in fiber arrays

We demonstrate that nonlinear optical fiber arrays can support stable solitonlike pulses with finite energy. The bound state that we have found is localized both in time and in spatial domain in the direction perpendicular to the pulse propagation. Numerical studies support our analytical conclusions.