This paper presents an overview of our recent work on the nanostructure optic-fiber and devices for optical signal processing. The most fundamental devices, nano-fiber based coupler and microring, are studied as examples. Experimental results show good agreement with theoretical analysis. A possible packaging method is proposed.
A novel optical coherence tomography (OCT) scheme is proposed based on an optical frequency comb (OFC) generator with single-sideband modulator. The OFC generator has a flat spectrum of 7.46-nm full width at half magnitude at 1550-nm band. By changing the comb interval around 10 GHz slightly, the detection depth is scanned through the imaging sample at high speed. Elimination of the coherence side-lobes of the generated optical comb is also studied by setting the OFC's seed laser at optimized wavelength. Tomography images of a glass cell with air or milk filled are successfully achieved with a spatial resolution of ~90 um, which can be further improved by using a gain-flattening filter in the OFC generator.
Three dimensional beam prpopapagation method is used to analyze the performance of multimode interference coupler based on general interference and restricted interference mechanisms. Numerical results show that couplers based on general interference are more preferable.
3D colloidal crystals in the cavity of fiber end face assembled by the natural sedimentation combined with isothermal heating evaporation induced self-assembly is investigated. Scanning electron microscopy images and transmittance spectra demonstrated the high ordered structure and optical qualities.
We demonstrate, by computer simulation, the feasibility 10-Gb/s shared by 64 subscribers is succeeded over the reach of 15 km of passive optical network (PON) by using optical orthogonal frequency division multiplexing (OFDM) signal modulation.
Prestressed fiber Bragg grating has been by use of femtosecond laser through annealing followed by rapid cooling. The grating obtained shows excellent thermal stability at the temperature up to 1200 °C.
An all-optical logic unit based on both FWM and XGM arising in a single SOA is proposed. Dual-channel logic AND, NOR, and XNOR gates for CSRZ-OOK signals could be simultaneously achieved without reconfiguration.
A bidirectional amplification module has been proposed for use in IP-over-CWDM networks. The amplification is provided by a bidirectional Er3+-doped fiber amplifier. The results of a bidirectional IP transmission experiment using the module clarified that the loss of the transmission fiber in the network could be compensated.
We demonstrate a cost-effective, 0.25 μm-CMOS compatible, silicon-based microring modulator with monolithically integrated grating couplers. High-speed NRZ modulations of 3 Gb/s and 3-dB coupling bandwidth of ~ 60 nm are realized.
A novel sunflower-type photonic crystal fiber with nonuniform air holes and nearly zero ultra-flattened dispersion is proposed.
A novel design of optical sampling systems based on SFG in PPLN is presented. A large phase-mismatch that is dependent on the pump wavelength and the PPLN length is used to suppress undesired pump-induced SHG.
An ac-coupled burst-mode receiver for 10-Gbit/s class PON systems has been developed by using a novel baseline-wander common-mode-rejection and inverted distortion technique. We achieved a settling time of less than 150 ns and a receiver sensitivity of -29.8 dBm at a bit error rate of 10(-3). This is the fastest value of any reported ac-coupled average-detection type burst-mode receiver for a 2(31)-1 pseudo random bit sequence.
A 1.0 μm-band supercontinuum with a flat spectral bandwidth of 6.0 nm is generated using a phase modulator, a dispersion medium and a photonic crystal fiber. The supercontinuum is employed as a multi-wavelength pulse source.
We demonstrate RZ-to-NRZ format conversion at 50Gbit/s based on silicon microring resonator with FSR of 100GHz. Bit error rate measurements show a low power penalty compared to electrical NRZ signal for error free operation.
we experimentally demonstrate a switchable multiwavelength fiber laser by using an in-fiber Mach-Zehnder interferometer, which is constructed with two double-cladding fibers. Multi-channel outputs are realized and can be controlled by the comb filtering of the in-fiber interference.
We carefully analyzed NF and output power depending on QW number and waveguide structure of MQW SOAs. The developed SOA with a NF of 3.7 dB can be used for a limiting or booster amplifier.
Highly thermal resistant and transparent Plastic Optical Fibre (POF) was successfully made from aromatic polyester called polyarylate (PAR) by which long distant transmission of visible light was achieved. The heat-resistant property, i.e., Tg of PAR POF was higher than those of other photonics polymers such as PMMA, Polycarbonate (PC), and Polystyrene (PSt). The Photo attenuations of PAR POF were found to be 1.0 dB/m and 0.6 dB/m at the wavelength of 650 nm and 760 nm, respectively. These results strongly indicate that the PAR POF can be applied as a novel optical cable material such as short distance optical cable especially for automobile information LAN and interconnection cable material.
Effective cutoff wavelength of bend insensitive fiber was estimated by measuring the angular splice loss as a function of wavelength. More accurate effective cutoff wavelength was obtained by the near-field method than the far-field method.
We report recent results about all-optical processing using QD-SOAs. Those include 160 Gb/s wavelength conversion by XGM and regenerative amplification up to 80 Gb/s obtained thanks to limiting amplification and detuned filtering of SPM.
The Internet has been population, which it was implement information technology, to every enterprize, also changed their contact mode of information flow style. Since public key conception was proposed, it had authentication function to secure while they are communication, and defense the data to leak based on stranger. In this article, we presented an improvement of generalized key agreement and password authentication protocol for multi-user, it avoid password guessing attack and reflection attack of impersonal goal. Users do not divulge their secret that still to authenticated owner each other.
