We successfully designed and fabricated TES bolometers utilizing Al/Ti bilayer TESs as sensitive thermometers.To reduce the intrinsic noise level and tune the saturation power of a bolometer,the TES thermometer is placed on a suspended SiN platform which is thermally coupled to the heat bath by four long SiN beams with different geometries.The measurement results show that the detectors have background limited noise performance,with a low noise equivalent power(NEP)on the order of10-17W/Hz1/2and have a saturation power of several tens pW at a bath temperature of 320 mK.These detectors are suitable for applications in ground-based astrophysics experiments by integrating absorbers for specific wavelengths.
We report the optical response characteristics of A1/Ti bilayer transition edge sensors （TESs）, which are mainly comprised of A1/Ti bilayer thermometers and suspended SiN membranes for thermal isolation. The measurement was performed in a 3He sorption refrigerator and the device＇s response to optical pulses was investigated using a pulsed laser source. Based on these measurements, we obtained the effective recovery time （τeff） of the devices at different biases and discussed the dependence of Veff on the bias. The device with a 940 μm × 940 μm continuous suspended SiN membrane demonstrated a fast response speed with τeff = 3.9 μs, which indicates a high temperature sensitivity （a = T/R·dR/dT = 326）. The results also showed that the TES exhibits good linearity under optical pulses of variable widths.
