Fabry-Perot Interferometer Based on Suspended Core Fiber for Detection of Gaseous Ethanol

An optical fiber tip sensor based on a Fabry–Perot interferometer is proposed for the detection of ethanol in the gas phase. The sensor is fabricated by fusion splicing one end of the suspended core fiber to a single mode fiber, whereas the other end is kept open to enable the interaction between the light propagating in the suspended core and the ethanol gas molecules. The sensor was tested with different percentages of ethanol, exhibiting a linear response between 0 and 100 wt.%, with a sensitivity of 3.9 pm/wt.%. The proposed sensor, with a length of a few hundred micrometers, can be an alternative solution for the detection of gaseous ethanol in foods or beverages, such as wines and distilled drinks.

High-Temperature Measurement of a Fiber Probe Sensor Based on the Michelson Interferometer

In this paper, a fiber probe high-temperature sensor based on the Michelson Interferometer (MI) is proposed and experimentally verified. We used a fiber splicing machine to fabricate a taper of the single-mode fiber (SMF) end. The high order modes were excited at the taper, so that different modes were transmitted forward in the fiber and reflected by the end face of the fiber and then recoupled back to the fiber core to form MI. For comparison, we also coated a thin gold film on the fiber end to improve the reflectivity, and the reflection intensity was improved by 16 dB. The experimental results showed that the temperature sensitivity at 1506 nm was 80 pm/°C (100 °C~450 °C) and 109 pm/°C (450 °C~900 °C). The repeated heating and cooling processes showed that the MI structure had good stability at a temperature up to 900 °C. This fiber probe sensor has the advantages of a small size, simple structure, easy manufacturing, good stability, and broad application prospects in industrial and other environments.

Optimization and Performance Analysis of Dispersion Compensation in RZ and NRZ Systems with Transmission Rates of 10 Gbps and 40 Gbps / Otimização e Análise da Compensação de Dispersão em Sistemas de RZ e NRZ com Taxas de Transmissão de 10 Gbps e 40 Gbps

Neste trabalho, investigamos um método de compensação de dispersão para as taxas de transmissão de 10 Gbps e 40 Gbps com formatos de modulação retorno ao zero (return to zero - RZ) e não retorno ao zero (non-return to zero - NRZ) usando fibra monomodo (single mode-fiber - SMF) e fibra compensadora de dispersão (dispersion compensating fiber - DCF). A influência da dispersão do compensador DCF com o aumento da potência do laser CW foi estudada, afim de se avaliar o desempenho dos sistemas de comunicação por fibra óptica aqui propostos. Os resultados da simulação foram validados através do formato do pulso, do espectro óptico e do diagrama de olho para a análise do fator Q e da taxa de erro de bit (bit error rate – BER).