Jiangde Peng

Dual-core photonic Crystal fiber for dispersion compensation

A novel design of dual-core photonic crystal fiber (DCPCF) consisting of pure silica and air is proposed in this letter. In addition to potential low loss, simulation shows that dispersion of this DCPCF can reach -18 000 ps/(nm/spl middot/km).

Study on noise characteristic of gain-clamped erbium-doped fiber-ring lasing amplifier

A simplified method to estimate the noise figure of the optically gain-clamped erbium-doped fiber amplifiers (EDFAs) is proposed. The simulation results indicate that the population inversion level at the signal input end dominates the noise performance of the entire amplifier. For a gain-clamped EDFA with ring-lasing configuration, the effects on the noise figure of the amplifier by the distributions of the pumping and lasing powers as well as the lasing wavelength are analyzed theoretically. The suggested noise-optimum configuration is co-pumping and co-traveling lasing oscillation at 1531 nm. Near quantum limit internal noise figure of 3.6 dB is achieved in the experiments under the best arrangement. The experiment results show perfect accordance with the theoretical analysis.

Vertical coupling between short range surface plasmon polariton mode and dielectric waveguide mode

Coupling performance between a short range surface plasmon polariton (SRSPP) mode and a conventional dielectric waveguide mode is demonstrated numerically. Simulation results show that the coupling length, as short as tens of microns, can be realized because the field of SRSPP extremely concentrates to the metal surface. SRSPP-based hybrid coupler provides not only an approach to realize highly compact functional devices, such as the TE-pass polarizer with high performance, but also an integratable route for efficiently exciting SRSPP mode, which is very useful in the SRSPP-based biosensor or SRSPP-assisted emission enhancement devices.

Highly efficient acoustooptic tunable filter based on cladding etched single-mode fiber

The efficiency enhancement of an acoustooptic tunable filter on cladding etched single-mode fiber (SMF) is investigated experimentally. When the fiber diameter is etched down to 30 /spl mu/m, the acoustooptic coupling efficiency from the LP/sub 01/ core mode to the LP/sub 11/ cladding mode was increased by an order of magnitude, and the RF power consumption was reduced by two orders of magnitude. A highly efficient 8-cm-long 25-/spl mu/m-thick AOTF on cladding etched SMF with an insertion loss of <0.2 dB, and RF power as low as 1.1 mW was demonstrated.

Opposite Goos-Hanchen shifts for transverse-electric and transverse-magnetic beams at the interface associated with single-negative materials

Goos-Hänchen shifts are investigated when total reflection occurs at the interfaces associated with single-negative materials (SNMs). A general rule for judging the direction of the Goos-Hänchen lateral shift concerning lossless media is obtained: Whether the lateral shift is positive or negative depends on the sign of micro1micro2 for TE-polarized incident beams and epsilon1epsilon2 for TM-polarized incident beams. It was theoretically demonstrated that, at the interface associated with SNMs, TE- and TM-polarized incident beams experience opposite Goos-Hänchen lateral shifts. An effective and simple approach to discriminating epsilon-negative material and micro-negative material is proposed.

Wavelength and power dependence of injected C-band laser on pump conversion efficiency of L-band EDFA

The effect of wavelength and power of an injected C-band laser on the pump conversion efficiency of a L-band erbium-doped fiber amplifier was studied via numerical simulation and experiment. In the studied C-band wavelength range of 1530-1560 nm, for higher injected power with longer wavelength, the backward output amplified spontaneous emission power is compressed more; but the residual laser power is greater due to the smaller emission coefficient at longer wavelength. Thus there is a best choice for injection wavelength and power. With an injection of -2 dBm at 1550 nm, 4.3 and 2.5 dB of gain enhancement for -12 and -2.6 dBm input at 1586 nm were achieved, respectively.

Zero dispersion slow light with low leakage loss in defect Bragg fiber

By introducing a defect layer into the periodic cladding of Bragg fiber, the core mode and the defect mode may anticross near their cutoff inside band gap. The defect location suppresses and flattens dramatically the group velocity (vg) of coupled core mode and the defect thickness changes gradually its dispersion. Theoretical investigation reveals zero dispersion and zero dispersion slope at various low vg’s can be achieved simultaneously at arbitrary wavelengths. Specially, the proper defect in the sixth bilayer leads to the lowest vg of 0.074 of light speed in vacuum at 1550nm. The optical energy is confined well in the core and the leakage loss is sufficiently low.

Polarization-entangled Bell states generation based on birefringence in high nonlinear microstructure fiber at 1.5 μm

Polarization-entangled photon pair generation based on two scalar scattering processes of the vector four- photon scattering has been demonstrated experimentally in high nonlinear microstructure fiber with birefringence. By controlling pump polarization state, polarization-entangled Bell states can be realized. It provides a simple way to realize efficient and compact fiber-based polarization-entangled photon pair sources.

Temperature dependence of ministop band in double-slots photonic crystal waveguides

We proposed and fabricated a double-slots photonic crystal waveguides (PCWGs) structure formed by introducing two slots into PCWGs with air-bridge structure on silicon-on-insulator substrate. The mode characteristics of double-slots PCWGs were investigated theoretically and experimentally. The transmission spectra present a sharp and deep dip (22 dB with bandwidth of 6 nm) caused by ministop band in the proposed structure, which is 15 dB deeper than that in the W3 PCWG. Additionally, dependence of the dip on temperature in the double-slots PCWG was measured and a temperature coefficient 0.159 nm/°C can be concluded.

Single polarization transmission in pedestal-supported silicon waveguides

In this Letter, properties of a pedestal-supported silicon waveguide are investigated, showing that it supports single polarization transmission. The pedestal is fabricated easily through a wet-etching process on strip waveguides. Theoretical analysis shows that this property is due to the leakage of quasi-TM mode when the pedestal width is small. A polarization extinction ratio larger than 20 dB at 1550 nm is measured in the pedestal waveguide sample, demonstrating single polarization transmission property experimentally. Thanks to its large single polarization transmission bandwidth, robustness in fabrication tolerance, and simple fabrication process, pedestal waveguides will have potential applications as simple silicon-integrated polarizers.