微机电系统红外脉冲光源调制特性的研究

针对微机电系统热激发红外光源的动态特性,采用一种新的计算方法。即通过建立光源在不同初始温度下升温与加电时间、功率之间的关系,定量估算不同脉冲频率下辐射功率的调制深度。该方法可以计算调制深度大情况下的动态特性。就其中两个重要影响因素加电方式和发射率分别进行讨论,得到:饱和功率相同的前提下,采用恒压源供电方式相比恒流源供电和恒定功率供电响应时间更小,从而更有利于改善光源的动态调制特性;相同条件下,选择高发射率的光源材料也有利于缩短上升时间。结合计算结果,对一个微型铂金薄膜红外光源的频响特性进行了验证测试,测试结果与计算分析符合较好。

Study on Modulation Characteristic of Micro-Electromechanical System Infrared Radiation Source

A new calculation method is adopted aiming at the dynamic charactetristic of a thermal induced micro-electromechanical system(MEMS) infrared radiation source.By calculating the temperature rise dependent on power supply time and power with different initial temperature,the modulation depth of radiation source under different pulse frequencies is quantitatively reckoned.This meathod is capable of calculating the dynamic characteristics with large modulation depth.The influence of power supply mode and material emissivity is discussed in detail.The results show that adopting constant voltage source obtains a shorter response time than by adopting constant current source or constant power source under the same saturated power condition,thus it is more advantageous for dynamic modulation characteristic improvement.Also,high emissivity material reduces the rise time without regard to other parameters change. Combining the calculated result,a test experiment is carried out to study the frequency response characteristic of a MEMS Pt thin film infrared source,and the experimental result fits the calculation well.