Demonstration of radio-over-fibre transmission of broadband MIMO over multimode fibre using mode division multiplexing

A novel method for sending MIMO wireless signals to remote antenna units over a single multimode fibre is proposed. MIMO streams are sent via different fibre modes using mode division multiplexing. Combined channel measurements of 2km MMF and a typical indoor radio environment show in principle a 2×2 MIMO link at carrier frequencies up to 6GHz. © 2012 Optical Society of America.

Hybrid cytomegalovirus-U6 promoter-based plasmid vectors improve efficiency of RNA interference in zebrafish

Short hairpin RNA (shRNA) directed by RNA polymerase III (Pol III) or Pol II promoter was shown to be capable of silencing gene expression, which should permit analyses of gene functions or as a potential therapeutic tool. However, the inhibitory effect of shRNA remains problematic in fish. We demonstrated that silencing efficiency by shRNA produced from the hybrid construct composed of the CMV enhancer or entire CMV promoter placed immediately upstream of a U6 promoter. When tested the exogenous gene, silencing of an enhanced green fluorescent protein (EGFP) target gene was 89.18 +/- 5.06% for CMVE-U6 promoter group and 88.26 +/- 6.46% for CMV-U6 promoter group. To test the hybrid promoters driving shRNA efficiency against an endogenous gene, we used shRNA against no tail (NTL) gene. When vectorized in the zebrafish, the hybrid constructs strongly repressed NTL gene expression. The NTL phenotype occupied 52.09 +/- 3.06% and 51.56 +/- 3.68% for CMVE-U6 promoter and CMV-U6 promoter groups, respectively. The NTL gene expression reduced 82.17 +/- 2.96% for CMVE-U6 promoter group and 83.06 +/- 2.38% for CMV-U6 promoter group. We concluded that the CMV enhancer or entire CMV promoter locating upstream of the U6-promoter could significantly improve inhibitory effect induced by the shRNA for both exogenous and endogenous genes compared with the CMV promoter or U6 promoter alone. In contrast, the two hybrid promoter constructs had similar effects on driving shRNA.

Precise modal excitation in multimode fibre for control of modal dispersion and mode-group division multiplexing

Each mode of a multimode fibre is excited using binary phase patterns on a Spatial Light Modulator and verified by observation of the near-field leaving the fibre and analysis of the step response. © 2011 OSA.

Adaptive enhancement of multimode fibre bandwidth by twin-spot offset launch

A binary grating on a Spatial Light Modulator generates twin antiphase spots with adjustable positions across the core of a multimode fibre allowing adaptive excitation of antisymmetric mode-groups for improving modal dispersion or modal multiplexing. © 2011 AOS.

Electro-optic integration of liquid crystal cladding switch with multimode passive polymer waveguides on PCB

Optical switching functionality is demonstrated in PCB integrated multimode passive polymer waveguides using a localised liquid-crystal cladding structure. Waveguide switching contrast of 15 dB is achieved with only 0.5 dB of on-state excess loss. © 2009 OSA.

The cytomegalovirus promoter-driven short hairpin RNA constructs mediate effective RNA interference in zebrafish in vivo

The ability to utilize the RNA interference (RNAi) machinery for silencing target-gene expression has created a lot of excitement in the research community. In the present study, we used a cytomegalovirus (CMV) promoter-driven DNA template approach to induce short hairpin RNA (shRNA) triggered RNAi to block exogenous Enhanced Green Fluorescent Protein (EGFP) and endogenous No Tail (NTL) gene expressions. We constructed three plasmids, pCMV-EGFP-CMV-shGFP-SV40, pCMV-EGFP-CMV-shNTL-SV40, and pCMV-EGFP-CMV-shScrambled-SV40, each containing a CMV promoter driving an EGFP reporter cDNA and DNA coding for one shRNA under the control of another CMV promoter. The three shRNA-generating plasmids and pCMV-EGFP control plasmid were introduced into zebrafish embryos by microinjection. Samples were collected at 48 h after injection. Results were evaluated by phenotype observation and real-time fluorescent quantitative reverse-transcription polymerase chain reaction (Q-PCR). The shGFP-generating plasmid significantly inhibited the EGFP expression viewed under fluorescent microscope and reduced by 70.05 +/- 1.26% of exogenous EGFP gene mRNA levels compared with controls by Q-PCR. The shRNA targeting endogenous NTL gene resulted in obvious NTL phenotype of 30 +/- 4% and decreased the level of their corresponding mRNAs up to 54.52 +/- 2.05% compared with nontargeting control shRNA. These data proved the feasibility of the CMV promoter-driven shRNA expression technique to be used to inhibit exogenous and endogenous gene expressions in zebrafish in vivo.

Symmetrical 2-D hermite-gaussian square launch for high bit rate transmission in multimode fiber links

A 2-D Hermite-Gaussian square launch is demonstrated to show improved systems capacity over multimode fiber links. It shows a bandwidth improvement over both center and offset launches and exhibits ±5 ìm misalignment tolerance. © OSA/OFC/NFOEC 2011.

Novel passive launch scheme for ultimate bandwidth improvement of graded-index multimode fibers

We propose a new practical multimode fiber optical launch scheme, providing near single mode group excitation for >5 times transmission bandwidth improvement. Equalization-free transmission of a 10-Gb/s signal over 220-m fiber is achieved in experimental demonstrations. © 2010 Optical Society of America.

20 Gb/s mode-group-division multiplexing employing Hermite-Gaussian launches over worst-case multimode fiber links

For the first time, mode group division multiplexing is achieved in a multimode fiber link using a 2-D Hermite-Gaussian mode launch. 20 Gb/s error-free transmission is achieved over a 250 m worst-case OM1 multimode fiber link. © OSA 2014.

Modal control of a 50μm core diameter multimode fiber using a spatial light modulator

An iterative, self-correcting system for doing modal control using adaptive optics in a 50μm core diameter multimode fiber (MMF) is designed. It is shown experimentally to reduce the number of modes generated by 300%. © 2006 Optical Society of America.

Modal control of a 50μm core diameter multimode fiber using a spatial light modulator

An iterative, self-correcting system for doing modal control using adaptive optics in a 50μm core diameter multimode fiber (MMF) is designed. It is shown experimentally to reduce the number of modes generated by 300%. © 2006 Optical Society of America.

Low loss and low crosstalk multimode polymer waveguide crossings for high-speed optical interconnects

Multimode polymer waveguide crossings exhibiting the lowest reported excess loss of 0.006dB/crossing and crosstalk values as low as -30dB are presented. Their potential for use in high-speed dense optical interconnection architectures is demonstrated. © 2007 Optical Society of America.

Statistical study of a novel launch scheme for highperformance electronic-equalized multimode-fiber links

A novel launch scheme is proposed for multimode-fiber (MMF) links. Enhanced performance in 10 Gb/s MMF links using electronic equalization is demonstrated by statistical analysis of installed-base fiber and an experimental investigation. © 2007 Optical Society of America.

10 Gb/s transmitter-based equalization for extended-reach multimode-fiber datacommunication links

Transmitter-based equalization is investigated for enhanced performance in 10 Gb/s multimodefiber links. Rigorous simulations and proof-of-principle experiments over 500 m of FDDI-grade fiber confirm for the first time the potential superiority of the technique relative to receiver-based schemes. © 2007 Optical Society of America.

Twin-spot launch for enhancement of multimode-fiber communication links

A novel twin-spot launch is proposed for multimode-fiber (MMF) links. Experimental and theoretical investigation of the launch indicates a penalty reduction of ≈50% of the 10 Gigabit Ethernet allocation for EDC-enabled links over worst-case MMF. © 2007 Optical Society of America.