Kızılötesi termo-mekanik dedektör dizini için optik okuma

Thermal Imaging has been a useful tool in many heat monitoring applications such as surveillance, target detection, biomedical imaging, monitoring circuits /machinery, insulation inspection and rescue. Among two main approaches to thermal imaging, namely cooled (photon detection) and uncooled thermal imaging (thermal detection); uncooled thermal imaging finds applications where low cost and fabrication simplicity is desired as well as performance. Theoretical analysis shows that performance of uncooled thermal detectors can potentially be increased by incorporating optical readout into MEMS structures. In this work; design, analysis, and testing of the optical readout for an uncooled infrared thermo-mechanical detector array (160x120 pixels) with integrated optical readout is reported.Detector operation is based on the conversion of heat caused by incident IR radiation to mechanical bending. This bending is detected by monitoring the first diffracted order of the readout beam returning from the diffraction gratings that are embedded underneath each detector. A scanned readout beam with single photodiode, staring photodiode, and staring CCD are the three different approaches that are explored for this monitoring purpose. Analysis on the optical readout system indicated that practically optical crosstalk free detection can be achieved by optimum spatial filtering. A detector to detector non uniformity correction method is also demonstrated. Utilization of this method by two coherent sources offers enhanced readout sensitivity in a broader thermal detection dynamic range.Experimental results indicated 0.92°K Noise Equivalent Temperature Difference (NETD) utilizing an 8 bit CCD camera is achieved. Calculations revealed <20mK NETD is achievable. Theoretical performance can be realized by the integration of 14 bit CCD camera or a photodiode array at the IR detector array readout.