Method and device for testing stray light characteristics of Digital Micro-mirror Device (DMD)
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摘要: 为了获得数字微镜器件(DMD)的真实光学特性,提出了微镜单元杂散光分布测试方法,并搭建实验装置对2×2阵列区域微镜单元的杂散光分布情况进行测试。提出了一种杂散光测试方法,并针对微镜单元尺寸小、配置方式灵活的特点,设计了汇聚光斑大小连续可调的照明系统以及可以对微镜单元清晰成像的成像系统。通过实验得到了2×2阵列区域微镜单元的杂散光分布情况。测试结果表明,单个微镜单元中心孔道位置附近反射的能量较强,靠近边缘位置反射的能量则相对较弱。此外,测试区域之外的微镜单元也会反射一部分能量,测试区域内微镜单元杂散光绝对强度最大值出现在中心孔道附近,其灰度值为6.86,紧邻测试区域微镜单元杂散光绝对强度最大值同样也出现在中心孔道附近,其灰度值为4.01,由此可以说明中心孔道位置附近的杂散光较强;测试区域内微镜单元的杂散光相对强度相对较弱,从测试区域边缘开始急剧增大,经过大约两个微镜单元后达到峰值,数值为293.5%,此后开始急剧下降。Abstract: In order to obtain the true optical characteristics of a Digital Micro-mirror Device (DMD), a test method for the stray light distribution of the micro-mirror unit was proposed and an experimental device was built to test the stray light distribution of a micro-mirror unit in the 2×2 array area.First, a stray light test method is proposed. Then, in view of the small size of the micro-mirror unit and the flexible configuration mode, an illumination system with a continuously adjustable convergent spot size and an imaging system that can clearly image the micro-mirror unit was designed. Finally, the stray light distribution of the micro-mirror unit in the 2×2 array area was obtained through experimentation.The test results show that the reflection energy near the center channel of a single micro-mirror unit is strong, while the reflection energy near the edge is relatively weak. In addition, the micro-mirror unit also reflects part of the energy outside the test area. The maximum absolute stray light intensity of the micro-mirror unit in the test area appears near the central channel, and its gray value is 6.86. The maximum absolute stray light intensity of the micro-mirror unit close to the test area also appears near the central channel, and its gray value is 4.01, which indicates that the stray light near the central channel is strong. The relative intensity of stray light in the test area is relatively weak, which increases sharply from the edge of the test area and reaches the value of 293.5% after about two micro-mirror units, and then decreases sharply.
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Key words:
- DMD /
- micro-mirror unit /
- stray light analysis /
- imaging properties /
- precision measurement
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表 1 前置镜头主要技术参数
Table 1. Main technical parameters of the front lens
指标名称 放大倍率 光圈 分辨率(1.0×放大倍率、
550 nm条件下)指标值 0.5×~1.0× 2.8~完全关闭 3.4 μm -
[1] 肖文健, 许振领, 周旋风. DMD红外场景产生器非均匀性校正方法研究[J]. 红外技术,2021,43(1):21-25.XIAO W J, XU ZH L, ZHOU X F. Nonuniformity correction of infrared scene simulator based on DMD[J]. Infrared Technology, 2021, 43(1): 21-25. (in Chinese) [2] 谢熙伟, 胡静, 沈亦兵. 基于数字微镜器件随机编码调制的相位成像[J]. 光学学报,2020,40(23):2311001. doi: 10.3788/AOS202040.2311001XIE X W, HU J, SHEN Y B. Phase imaging based on random coding modulation of digital micro-mirror device[J]. Acta Optica Sinica, 2020, 40(23): 2311001. (in Chinese) doi: 10.3788/AOS202040.2311001 [3] 张冬华, 王晓荣, 郑蕊, 等. 基于DMD的拉曼光谱检测模块设计[J]. 仪表技术与传感器,2020(11):33-35,39. doi: 10.3969/j.issn.1002-1841.2020.11.007ZHANG D H, WANG X R, ZHENG R, et al. Design of Raman spectral detection module based on DMD[J]. Instrument Technique and Sensor, 2020(11): 33-35,39. (in Chinese) doi: 10.3969/j.issn.1002-1841.2020.11.007 [4] LI SH B, LIANG R G. DMD-based three-dimensional chromatic confocal microscopy[J]. Applied Optics, 2020, 59(14): 4349-4356. doi: 10.1364/AO.386863 [5] 苏渝阳, 王治乐, 陆敏, 等. 红外目标模拟系统DMD成像非均匀性分析及校正[J]. 应用光学,2020,41(5):1074-1081. doi: 10.5768/JAO202041.0506002SU Y Y, WANG ZH L, LU M, et al. Nonuniformity analysis and correction of DMD imaging in infrared target simulation system[J]. Journal of Applied Optics, 2020, 41(5): 1074-1081. (in Chinese) doi: 10.5768/JAO202041.0506002 [6] 李轶庭, 王灵杰, 张玉慧, 等. 天基平台宽谱段成像光学系统设计[J]. 中国光学,2021,14(6):1495-1503. doi: 10.37188/CO.2019-0255LI Y T, WANG L J, ZHANG Y H, et al. Optical design of visual and infrared imaging system of space-based platform[J]. Chinese Optics, 2021, 14(6): 1495-1503. (in Chinese) doi: 10.37188/CO.2019-0255 [7] CHLIPALA M, KOZACKI T. Color LED DMD holographic display with high resolution across large depth[J]. Optics Letters, 2019, 44(17): 4255-4258. doi: 10.1364/OL.44.004255 [8] ZHOU J, QIAO Y, SUN ZH, et al. Design of a dual DMDs camera for high dynamic range imaging[J]. Optics Communications, 2019, 452: 140-145. doi: 10.1016/j.optcom.2019.07.008 [9] LU B W, CUI X F, JIN G, et al. Effect of La2O3 addition on mechanical properties and wear behaviour of NiTi alloy fabricated by direct metal deposition[J]. Optics &Laser Technology, 2020, 129: 106290. [10] 王美昌, 于斌, 张炜, 等. 基于数字微镜器件的数字线扫描荧光显微成像技术[J]. 物理学报,2020,69(23):238701. doi: 10.7498/aps.69.20200908WANG M CH, YU B, ZHANG W, et al. Digital line scanning fluorescence microscopy based on digital micromirror device[J]. Acta Physica Sinica, 2020, 69(23): 238701. (in Chinese) doi: 10.7498/aps.69.20200908 [11] 陈雪旗, 姜爱民, 莫小范. 基于DMD的时变目标模拟研究[J]. 天文研究与技术,2020,17(3):357-365.CHEN X Q, JIANG A M, MO X F. Time-varying source simulation research based on digital micromirror device[J]. Astronomical Research and Technology, 2020, 17(3): 357-365. (in Chinese) [12] 张一, 余卿, 张昆, 等. 基于数字微镜器件的并行彩色共聚焦测量系统[J]. 光学 精密工程,2020,28(4):859-866.ZHANG Y, YU Q, ZHANG K, et al. Parallel chromatic confocal measurement system based on digital micromirror device[J]. Optics and Precision Engineering, 2020, 28(4): 859-866. (in Chinese) [13] 李卓, 叶宗民, 牟达. 基于DMD的长波红外景象生成器分光构架设计[J]. 长春理工大学学报(自然科学版),2019,42(5):37-40,56.LI ZH, YE Z M, MU D. Design of spectrum frame of LWIR scene simulator based on DMD[J]. Journal of Changchun University of Science and Technology (Natural Science Edition) , 2019, 42(5): 37-40,56. (in Chinese) [14] 姚雪峰, 崔继承, 尹禄, 等. 中阶梯光栅光谱仪波段范围校正装置[J]. 光学 精密工程,2017,25(2):304-311. doi: 10.3788/OPE.20172502.0304YAO X F, CUI J CH, YIN L, et al. Calibration devices for band range of echelle spectrometer[J]. Optics and Precision Engineering, 2017, 25(2): 304-311. (in Chinese) doi: 10.3788/OPE.20172502.0304 [15] 邢思远, 王超, 徐淼, 等. 数字微镜器件超分辨成像光学系统装调误差影响研究[J]. 中国光学,2021,14(5):1194-1201.XING S Y, WANG C H, XU M, et al. Influence of alignment error on DMD super-resolution imaging optical system[J]. Chinese Optics, 2021, 14(5): 1194-1201. (in Chinese) [16] 吕博, 冯睿, 寇伟, 等. 折反射式空间相机光学系统设计与杂散光抑制[J]. 中国光学,2020,71(4):822-831.LV B, FENG R, KOU W, et al. Optical system design and stray light suppression of catadioptric space camera[J]. Chinese Optics, 2020, 71(4): 822-831. (in Chinese)