An optimization technique is presented for the radio over fiber (ROF) wireless local area network (WLAN) transmission in IM/DD optical link. The results show that with minimal optimization, directly modulated ROF WLAN 802.11g signal at 2.4 GHz and externally modulated 1.25 Gbps baseband signal can coexist in the 2 km IM/DD optical link with a power penalty of 3 dB. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:812–815, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25029

No abstract

Vernier and Fano resonances are promising approaches for enhancing the sensitivity of an alloptical sensor. A theoretical analysis was performed to integrate a Fano-like resonance shape with a Vernier resonance by considering the presence of partial reflective end facets at a double microring resonator waveguide. The system was developed based on scattering matrix and optical transfer function. The double and all-pass racetrack microring configurations were compared with and without the end facet at the waveguide to analyze the dynamic change of the output resonance spectrum. The spectrum were analyzed based on the free spectral range and resonance pattern. The resonator systems were applied to refractive index-based sensing protocol, which was operated by a shift of resonance wavelength with a change of refractive index. The sensitivity was optimized by varying the configuration parameters such as the radius of the ring, the distance between end facet, and the coupling coefficients. Integrating Vernier spectrum with Fano resonance improved the sensitivity for all-pass racetrack configuration by 5.16 % and the sensitivity for double racetrack configuration by 6.31 %. The recorded limit of detection (LOD) of double racetrack was 3.30 × 10 -5 .

We demonstrate a broad bandwidth multiwavelength laser based on a bidirectional Lyot filter and a semiconductor optical amplifier with a mechanism of intensity-dependent loss as the flatness agent. A wide bandwidth of a multiwavelength spectrum of 32.9 nm within a 5 dB uniformity is obtained under optimized polarization parameters. For this case, the number of generated lasing lines is 329 with a fixed wavelength separation of 0.1 nm. The power stability of this multiwavelength laser is less than 1.35 dB within 200 min time frame. This shows that the bidirectional Lyot filter provides an alternative option for multiwavelength generation in laser systems.

Full text PDF References Request permissions