TY - THES A1 - Xu, Zhiming T1 - Electronic circuit design and implementation of a contactless optical position measurement device N2 - This thesis presents the design and implementation of a low-cost, highprecision analog front-end for a non-contact optical displacement measurement system. While the principle of sensing based on D-shaped optical fibers is well-established, its practical replication faces challenges of poor consistency from manual polishing and high material costs. To address these issues, we employ 3D-printed polymer waveguides as the core sensing medium and design a dedicated signal conditioning circuit to accompany it. The core work of this thesis revolves around a dual-channel, two-stage amplifier analog front-end. The circuit converts weak, nanoampere-level (nA) photocurrents from the photodiodes into voltage signals. These signals are stable, linear, and suitable for the microcontroller (MCU) to process. The entire design follows this workflow: starting from theoretical calculations, the circuit’s performance in frequency domain, time domain, and noise was verified through LTspice simulation. Subsequently, the design was realized in hardware via PCB implementation, including guard rings. The experimental results show that the performance of the fabricated circuit is consistent with simulation. When integrated with the 3D-printed waveguide, the complete system performed end-to-end calibration and decoding. Over a 50 mm measurement range, the system achieved a maximum absolute error of less than 0.81 mm and a root mean square error below 0.4 mm. This research validates the feasibility of a complete, low-cost, non-contact displacement measurement solution—from the sensing structure to the signal processing—suitable for small-scale use. Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-85201 CY - Regensburg ER -