数字微镜器件(DMD)杂散光特性测试方法及装置

Method and device for testing stray light characteristics of Digital Micro-mirror Device(DMD)

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。

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 en-ergy 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 chan-nel,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.