This paper presents a new type of distributed Fiber Bragg grating (FBG) sensing system based on a tunable pulse laser. The system has 500 gratings with same centre wavelengths of 1550 nm and the spacing of every grating is 3m. All gratings have been packaged and 27m delay lines are inserted between every two adjacent gratings. The scanning periodic time of tunable pulsed laser is 0.25 s; the scanning range is 1545 ~ 1555 nm; the laser pulse line width is 0.18 nm. If the grating temperature was constant, only the 1550 nm light was reflected back. But with temperature change, the grating central wavelength changed and the corresponding light pulse was reflected back. The light signals are converted to voltage pulses by the photoelectric detector and sampled by high-speed acquisition card at the 500 Msps sampling rate. The data processing system send out the voltage signals to control laser and compares these voltage signals with those sampled signals. Program will calculate the offset which linear corresponding to the gratings temperature change. In addition, reflected optical signals of different positions need different time, and the time interval of adjacent grating is 200 ns. By detecting and calculating the interval time of reflected light, the location and the temperature of the grating whose temperature has changed will obtain. Experimental results showed that grating temperature sensitivity rose at 11.4 pm/℃. The deviation between the measured temperature and the actual temperature is within 5% range. This system not only can monitor the temperature, but also can determine the location. It can meet monitoring hundreds or even thousands of different locations simultaneously. Therefore it has broad application prospects.

A compact temperature sensor based on a fiber loop mirror (FLM) combined with a liquid-filled high-birefringent photonic crystal fiber (HiBi-PCF) is designed and numerically analyzed. A quite high temperature sensitivity of 1.87 nm/ºC can be achieved.

In this paper, a portable near-infrared spectroscopy (NIR) analyzer was developed with the semiconductor refrigerating InGaAs array near-infrared spectrometer. A constant temperature transmission cell sample was designed, and the spectral analysis software was developed, and the calibrtion models were established for the analyzer. Take the 54 rice wine samples as the main detected objective, the calibration models of alcohol and non-sugar solids in the rice wine were built with the pretreatment of 2nd derivative and 1st derivative. The R2 is 99.94% for alcohol and 99.29% for non-sugar solids; the root mean squared error of prediction (RMSEP) is 0.259% for alcohol and 0.0134% for non-sugar solids; the relative standard deviation (RSD) are respectively 2.194% and 3.396%. It suggested that the portable NIR rice wine analyzer could be a fast and reliable alternative for rice wine quality testing.

Chemical oxygen demand (COD) is a synthetical indicator which represents the degree of organic pollution in water. The near-infrared (NIR) transmission and the UV absorbance method based on photoelectric detection technology and spectroscopy analysis have some advantages such as high precision, fast, non-contact, no secondary pollution etc compared to conventional wet chemical method. The NIR transmission spectra and UV absorbance spectra of standard solution configured with phthalate hydrogen potassium were collected respectively by MPA FT-IR spectrometer (Bruker Optics Inc.) made in Germany and AvaSpec-2048-2 UV sepctrometer (Avantes Inc.) made in Netherlands. After different pretreatment to the spectra, COD quantitative analysis model was established using partial least squares regression (PLS) and linear regression. The statistical analysis of COD quantitative model was implemented, and the result showed that UV absorbance meathod had a higher relevance but lower forecast accuracy and precision than NIR transmission method.

Core/shell CdSe /ZnS quantum dots (QDs) were synthesized by thermal deposition using cadmium oxide and selenium as precursors in a hot lauric acid and hexadecylamine trioctylphosphine oxide hybrid. The CdSe/ZnS QDs exhibited high photoluminescence efficiency with a quantum yield more than 41%, and size-tunable emission wavelengths from 500 to 620 nm. White light-emitting diode with CIE coordinates of (0.319, 0.32) was fabricated by combining blue InGaN chip with CdSe /ZnS QDs.