Jin-Chen Chiu

Concentration effect of carbon nanotube based saturable absorber on stabilizing and shortening mode-locked pulse

We comprehensively investigated the concentration effect of dispersed single-walled carbon nanotubes (SWCNTs) in polymer films for being a saturable absorber (SA) to stabilize the mode locking performance of the erbium-doped fiber laser (EDFL) pulse through the diagnosis of its nonlinear properties of SA. The measured modulation depth was from 1 to 4.5% as the thickness increased 18 to 265 microm. The full-width half-maximum (FWHM) of the stable mode-locked EDFL (MLEDFL) pulse decreased from 3.43 to 2.02 ps as the concentrations of SWCNTs SA increased 0.125 to 0.5 wt%. At constant concentration of 0.125 wt%, the similar pulse shortening effect of the MLEDFL was also observed when the FWHM decreased from 3.43 to 1.85 ps as the thickness of SWCNTs SA increased 8 to 100 microm. With an erbium-doped fiber length of 80 cm, the shortest pulse width of 1.85 ps were achieved at 1.56 microm with a repetition rate of 11.1 MHz and 0.2 mW of the output power under an output coupling ratio of 5%. An in-depth study on the stable mode-locked pulse formation employing SWCNTs SA, it is possible to fabricate the SWCNT films for use in high performance MLEDFL and utilization of many other low-cost nanodevices.

Pulse shortening mode-locked fiber laser by thickness and concentration product of carbon nanotube based saturable absorber.

The dependence of thickness and concentration product (TCP) of single-wall carbon nanotubes saturable absorber (SWCNTs SA) on stabilizing and shortening pulsewidth in mode-locked fiber lasers (MLFLs) was investigated. We found that an optimized TCP for pulse energy and nonlinear self-phase modulation (SPM) enabled to determine the shorter pulsewidth and broader 3-dB spectral linewidth of the MLFLs. The shortest MLFL pulsewidth of 418 fs and broad spectral linewidth of 6 nm were obtained as the optimized TCP was 70.93 (μm•wt%), which was in good agreement with the area theorem prediction. This significant effect of TCP on pulse energy, SPM, pulsewidth, and spectral linewidth of MLFLs suggests that the TCP represents the total amount of SWCNTs in SA, which can be used as one of important and key parameters for characterizing the passive MLFL pulsewidth.

New Package Scheme of a 2.5-Gb/s Plastic Transceiver Module Employing Multiwall Nanotubes for Low Electromagnetic Interference

A novel polymer-based multiwall carbon nanotube (MWCNT) with high shielding effectiveness (SE) for use in packaging a 2.5-Gb/s plastic transceiver module is demonstrated. The MWCNT composites are tested to evaluate the electromagnetic (EM) shielding against emitted radiation from the optical transceiver modules. The results show that the SE of MWCNT composite packages exhibit 38-45 dB in the far-field source and 28-40 dB in the near-field source at a frequency range of 1-3 GHz, and an average of 14 dB for the optical transceiver modules at a frequency of 2.5 GHz. The MWCNT composites with their high SE are potentially suitable for packaging low-cost and low-EM-interference optical transceiver modules used in Gigabit Ethernet or fiber-to-the-home lightwave transmission systems

High-Performance Electromagnetic Susceptibility of Plastic Transceiver Modules Using Carbon Nanotubes

A high-performance electromagnetic susceptibility (EMS) of plastic transceiver module using carbon nanotube (CNT) composites is proposed. The shielding effectiveness (SE) of the CNT composites increases as the weight percentage of the CNTs increases. The SE of CNT composites with 50% weight percentage CNTs exhibits 38-45 dB. The EMS performance is experimentally evaluated by the eye diagram and bit-error-rate test for a 2.5-Gbps lightwave transmission system. The results show that the eye diagram and power penalty caused by the radiated interference of the plastic transceiver modules are dependent on the EMS. The plastic transceiver modules with the more weight percentage of the CNTs exhibit a higher SE, and hence show effective EMS performance, a better mask margin, and a lower power penalty. The likely cause for effective EMS performance with higher weight percentage CNTs of the plastic transceiver modules is due to the high-aspect ratios of CNTs, more structural to form overlapping conductive networking to provide high SE. Therefore, the CNT composites with their high SE are suitable for packaging high-performance EMS optical transceiver modules used in fiber to the home (FTTH) lightwave transmission systems

Passively mode-locked lasers using saturable absorber incorporating dispersed single-wall carbon nanotubes

Passively mode-locked lasers using saturable absorber incorporating dispersed single-wall carbon nanotubes (SWCNTs) is demonstrated. The peak absorption wavelength of saturable absorber can be engineered within the gain band-width of erbium-doped fiber (EDF) centered at 1550 nm. The mean diameter of SWCNTs and the linear optical absorption of SWCNTs-polyvinyl alcohol (PVA) film are verified by Raman spectroscopy and UV-Visible-NIR spectrophotometer. By integrating the SWCNTs-PVA film into EDF ring laser (EDFL) centered at 1550 nm, we observed three pulse mode operations, Q-switching, mode-locking, and 5th-order harmonic mode-locking. The measured pulsewidths of the mode-locking and 5th harmonic mode-locking EDFL are 4.2 ps and 2.7 ps, respectively

High Electromagnetic Shielding of a 2.5-Gbps Plastic Transceiver Module Using Dispersive Multiwall Carbon Nanotubes

A novel polyimide film, consisting of finely dispersed multiwall carbon nanotubes (MWCNTs) in an ionic liquid (IL), is demonstrated to be high shielding effectiveness (SE) for use in packaging a 2.5-Gbps plastic transceiver module. The IL-dispersed MWCNT composite exhibits a high SE of 40 ~ 46 dB. By comparison, the composite fabricated by nondispersive process requires a higher loading of MWCNTs at 50 wt- % than the IL-dispersed process at only 30 wt-%. The electromagnetic susceptibility (EMS) performance is experimentally evaluated by the eye diagram and bit-error-rate for a 2.5-Gbps lightwave transmission system. The package housing fabricated by the dispersive MWCNT composites shows an enhanced EMS performance, an improved mask margin, and a lower-power penalty. These results indicate that the IL-dispersed MWCNT composites are suitable for packaging low-cost and high-performance optical transceiver modules used in the fiber to the home lightwave transmission systems.

Electromagnetic Shielding Performance for a 2.5 Gb/s Plastic Transceiver Module Using Dispersive Multiwall Carbon Nanotubes

Electromagnetic (EM) shielding performance for a plastic composite by employing polyimide-based dispersive multiwall carbon nanotubes (MWCNTs) is presented. A well-dispersed MWCNT composite offers a higher electrical conductivity with a lower weight percentage of MWCNTs. The dispersive MWCNT composites with their high shielding effectiveness (SE) are suitable for packaging low-cost optical transceiver modules used in fiber to the home (FTTH) lightwave transmission systems.

High-performance electromagnetic susceptibility for a 2.5Gb/s plastic transceiver module using multi-wall carbon nanotubes

High-performance electromagnetic susceptibility (EMS) for a 2.5Gb/s optical transceiver module is first demonstrated by polymer-based multi-wall carbon nanotubes (MWCNT). The EMS performance is experimental evaluated by the eye diagram and bit-error-rate test for a 2.5Gb/s lightwave transmission system. The plastic transceiver modules with the more weight percentage of the MWCNT exhibit a higher shielding effectiveness (SE), and hence show effective EMS performance, a better mask margin, and a lower power penalty. The MWCNT composites with SE are suitable for packaging low-cost and high-performance EMS optical transceiver modules used in fiber to the home (FTTH) lightwave transmission systems

Dynamic operation of passive mode-locked fiber laser with carbon nanotubes-based saturable absorber

Measurement and modeling of single-walled carbon nanotubes (SWCNTs) based saturable absorber (SA) on stabilizing and shortening mode-locked fiber lasers are presented. The concentration and thickness effect of SWCNTs SA on stabilizing and shortening passive mode-locked pulse is investigated experimentally. Haus master equation is applied to simulate the pulse characteristics to understand the dynamic operation of passive mode-locked fiber lasers. The simulation results are in good agreement with the experimental results for the spectral bandwidth and pulse width depended on the thickness and concentration of SWCNTs SA. A limit of spectral bandwidth of 6.04 nm and pulse width of 440 fs in passive mode locking lasers is obtained. A comprehensively study of pulse characteristics of passive mode-locked fiber lasers provides a guide to fabricate an effective SWCNTs SA for use in many carbon nanotubes based photonics devices.

High electromagnetic shielding of multi-wall carbon nanotube composites using ionic liquid dispersant

A 2.5 Gbps optical transceiver module fabricated by ionic liquid (IL)-dispersed multi-wall carbon nanotube (MWCNT) composites is demonstrated. In comparison with shielding effectiveness (SE) measurements without dispersion, IL- dispersed MWCNT composites exhibited high SE of 40-46 dB at lower weight percentage of MWCNTs. Ionic charge force and alkyl groups interaction in the IL-MWCNT hybrid solution are the dominant mechanisms to determine a well- dispersed MWCNT composite. To develop a cost effective material for use in packaging an optical transceiver module, a fine dispersion of MWCNTs in the polymer matrices and association with the dispersion mechanism is essential.