Upconversion detector for range-resolved DIAL measurement of atmospheric CH₄

Abstract

We demonstrate a robust, compact, portable and efficient upconversion detector (UCD) for a differential absorption lidar (DIAL) system designed for range-resolved methane (CH) atmospheric sensing. The UCD is built on an intracavity pump system that mixes a 1064 nm pump laser with the lidar backscatter signal at 1646 nm in a 25-mm long periodically poled lithium niobate crystal. The upconverted signal at 646 nm is detected by a photomultiplier tube (PMT). The UCD with a noise equivalent power around 127 fW/Hz outperforms a conventional InGaAs based avalanche photodetector when both are used for DIAL measurements. Using the UCD, CH DIAL measurements have been performed yielding differential absorption optical depths with relative errors of less than 11% at ranges between 3 km and 9 km.

Infrared Optical Observability of an Earth Entry Orbital Test Vehicle Using Ground-Based Remote Sensors

“…Imaging is associated with the field of view (FOV) and the resolution of the detection system. Usually, the FOV of the scanning telescope has a wide range of 0.01-100 mrad [52][53][54]. As the FOV and the detection distance increase, the number of pixels receiving the TIR irradiance decreases.…”

Upconversion raster scanning microscope for long-wavelength infrared imaging of breast cancer microcalcifications

“…The upconverted spectrum shows a good agreement with FTIR spectrum. Generally, upconversion detection gives a superior SNR at low signal levels (high absorbance's due to the very low dark noise in the Si detector) [28,29]. This is highly pertinent to the highly absorbing breast calcifications, and may allow for the use of thicker samples.…”

Enhancing the detectivity of an upconversion single-photon detector by spatial filtering of upconverted parametric fluorescence

“…4(c) is the angular profile of the USPDC photon count rate obtained by integrating Fig. 4(b) over the λ s axis (i.e., a range that, on the upconverted side, corresponds to the 635 ± 5 nm pass-band of the filter used in the experiment), and the blue dash curve is the |G(Δk d )| 2 [13], where G(Δk d ) is the Fourier transform of g(z), and Δk d is given by Eq. 2and Eq.…”

“…In principle, we can further improve η up by increasing the pump power. Using a similar UCD design (Λ = 12.07 μm, λ s = 1646 nm), we have previously demonstrated that a 160 W pump with optimal spatial overlap with the signal can achieve η up as high as 45% [2]. In this work, a moderate pump power was used to maintain a stable operation of the UCD over the range of operating temperature in which USPDC noise was investigated.…”

“…Frequency upconversion is a promising technology for infrared (IR) detection, and it has already been demonstrated in applications such as hyperspectral imaging [1], gas sensing [2] and single-photon counting [3][4][5]. Instead of measuring an IR signal directly, it is first mixed with a high-intensity pump field in a second-order nonlinear crystal and upconverted into a signal at the visible or near-IR range, which can then be detected by high-performance silicon or InGaAs based detector.…”