Linearly excited indium fluorescence imaging for temporally resolved high-precision flame thermometry

Abstract

Two-line atomic fluorescence (TLAF) is a promising technique for two-dimensional (2D) flame thermometry. However, it suffers either from a low signal-to-noise ratio (SNR) when excited in the linear regime or a quenching effect and nonlinear behavior in the nonlinear regime. This work aims to develop a new TLAF modality, which can overcome the aforementioned limitations based on a specifically designed laser source that can generate long pulses ( ∼ 400 n s ) with a moderate energy of ∼ 0.9 µ J and operate at a repetition rate up to ∼ 22 k H z . A proof-of-concept experiment was conducted and linearly excited fluorescence images with an SNR up to ∼ 14 were obtained within 1 ms acquisition time by synchronizing the laser with the microchannel plate (MCP) of a 10 Hz-rate intensified camera. The SNR achieved was comparable to that of a traditional nonlinear TLAF implementation and superior to a conventional linear TLAF approach. This approach offers a novel solution for recording linearly excited indium fluorescence images and is expected to make TLAF a temporally resolved and high-precision 2D thermometry for the first time.

Noninvasive measurement of temperature for simulated tissue based on piezoelectric micromachined ultrasonic transducers

“…Noninvasive temperature measurement is important not only in the industry such as combustion process monitoring [1] and steal manufacturing process [2], but also in biomedical applications such as temperature feedback in thermal therapy [3,4]. High-intensity focused ultrasound (HIFU) as a burgeoning * Author to whom any correspondence should be addressed.…”