对镱铒共掺硫氧化钇红外上转换材料的远场探测与识别

为推进红外上转换材料的远距离应用,以镱铒共掺硫氧化钇为例,研究红外上转换材料标靶的远距离探测与识别。采用改进的硫熔法合成制备在1.5 m波长附近有较强吸收、在980 nm附近有较强辐射的镱铒共掺硫氧化钇材料,并将该材料涂覆在铝板表面制作900 mm900 mm的标靶。考虑材料具有转换效率较低,激发荧光寿命长,从而对入射光脉冲具有毫秒级的显著展宽等特点,采用脉宽8 ns、单脉冲能量5 mJ 、波长为1 550 nm的激光脉冲激发,并采用BASLER相机(acA1300-60 gmNIR,截止波长1 000 nm)获取标靶图像进行探测,采用中心波长为980 nm的带通滤光片滤除环境光干扰,从而提高辨识度。通过帧差法等图像处理过程在所采集的标靶图像中提取激发光斑。分别在50 m、55 m、60 m、65 m、70 m和76 m距离上进行重复探测试验,测试结果表明:识别率可达98.3%。

Long range detection and recognition of IR upconversion material Y2O2S:Yb,Er

In order to propel the application of infrared up-conversion materials at long distance, the detection and recognition of the Ytterbium Erbium co-doped Yttrium Oxysulfide(Y2O2S:Yb,Er) were explored. The Y2O2S:Yb,Er material with an 1.5 m peak absorption and a 980 nm peak emission was prepared through an improved sulfur melting method, and was coated on a 900 mm900 mm aluminum plate to form a target. Due to the fact that the prepared material has a relative low conversion efficiency and a long fluorescence radiating period, which tends to broaden the exciting laser pulse, the target was then excited by a laser pulse of 1 550 nm wavelength, 8 ns pulse width and 5 mJ/pulse energy. The image of the target was collected by a BASLER camera with a 1 000 nm cutoff wavelength. A dedicated band pass filter with a 980 nm central wavelength and a 100 nm bandwidth was employed to suppress the interference caused by ambient light, realizing a higher signal to noise ratio. The excited spot was extracted from the acquired image of the target through simple frame differentiating image processing, so as to achieve far range detection and recognition. Test results obtained respectively at 50 m, 55 m, 60 m, 65 m, 70 m and 76 m indicate that the recognition rate reaches 98.3%.