Background

Time-correlated single-photon counting (TCSPC) is the key enabling technology for applications such as low-light fluorescence lifetime spectroscopy, time-gated Raman spectroscopy, and photon counting time-of-flight (ToF) 3D imaging. For these applications, the most important figure- of-merit is the single-photon timing resolution that directly affects the measurement accuracy and precision on important parameters such as the fluorescence-decay lifetime, Raman spectral resolution, ToF distance, and spatial resolution. The TCSPC single-photon time resolution is currently limited by the available single-photon detector technology.

Technology Overview

CU Boulder researchers have demonstrated a time-magnified TCSPC (TM-TCSPC) that achieves an unprecedentedly short single-photon timing resolution of 550 femtoseconds using an off-the-shelf single photon detector. The key component is a quantum temporal magnifier. A temporal magnification of 130x with a 97% photon conversion efficiency has been achieved while maintaining the quantum coherence of the signal under test. When applied to photon counting ToF 3D imaging, the TM-TCSPC greatly suppresses the range walk error by 99.2 % and thus provides high depth measurement accuracy and precision of 26 μm and 3 μm, respectively.

Benefits

• Sub-picosecond resolution
• Enhanced resolution for ToF 3D imaging
• No need for cryogenic cooling

Applications

• Photon counting time-of-flight imaging
• Low-light fluorescence lifetime spectroscopy and microscopy
• Time-gated Raman spectroscopy