Overview

Current Projects

• Non-destructive damage detection in structures by microwave Time Domain Reflectometry (TDR)

• Non-destructive damage detection in structures by Optical Time Domain Reflectometry (OTDR)

Research Interests

Professor Hunsperger’s research program encompasses many aspects of photonic and microwave devices and circuits. He has worked on semiconductor distributed feedback (DFB) lasers, light emitting diodes (LEDs), metal-semiconductor-metal (MSM) photodiodes, acousto-optic modulators and a light emitting and detecting (LEAD) laser diode. Some of these devices have been incorporated into optical integrated circuits (OICs) or photonic integrated circuits (PICs). In the microwave area, he has made field effect transistors (FETs) that can operate at frequencies as high as 20 GHz. And diode up-converters operating as high as 40 GHz. Dr. Hunsperger’s most recent work has been focused on the problem detection and evaluation of corrosion of steel reinforcement in concrete structures. In a collaborative project with the Civil and Environmental Engineering Department, he has used the method of time domain reflectometry (TDR) to detect corrosion of steel tensioning cables in bridge beams and in the supporting cables of suspension bridges. In TDR a microwave pulse is transmitted along the length of the cable under test. Reflections that occur at any corrosion site or other defect can be analyzed electronically to locate the site of the defect and to determine its severity. Systems designed under this project have been installed in three highway bridges in Delaware for field testing. Currently, Dr. Hunsperger is exploring the possibility of using optical time domain reflectometry (OTDR) over a glass or plastic waveguiding fiber to detect corrosion in steel reinforced structures.