Μm Detector Research Articles

Ultrawideband sub-pascal sensitivity piezopolymer detectors

Piezoelectric detectors are integral part of modern ultrasound imaging systems. Their utility has also been extended beyond the established methodologies into the emerging realm of hybrid optoacoustic imaging. Conventional piezoceramic detectors, however, struggle to combine high detection sensitivity with ultrawide bandwidth, both considered critical for attaining optimal optoacoustic imaging performance. Our research, both theoretical and empirical, unveils that damped piezopolymer detectors fabricated from PVDF-TrFE are markedly capable of achieving a synergistic blend between broad bandwidth and superb sensitivity. Experimental evaluations reflected an average sensitivity of 15.5 µV/Pa within a 1–10 MHz band for a 120 µm thick detector and 6.4 µV/Pa within a 1–30 MHz band for a 20 µm thick detector, thus outperforming conventional piezoelectric analogues. The resultant noise equivalent pressure (NEPs) values were 0.3 Pa and 1.2 Pa for the 20 µm and 120 µm detectors, respectively. Our findings herald a significant stride towards enhancing the efficacy of ultrawideband ultrasound and optoacoustic imaging systems.

The Silicon Charge Detector of the High Energy Cosmic Radiation Detection experiment

The High Energy Cosmic Radiation Detector (HERD) is an experiment designed for direct measurement of cosmic rays on the Chinese Space Station in 2027. Its goals include precise measurements of cosmic ray energy spectra, mass composition, electron/positron spectra, cosmic rays anisotropy, gamma ray astronomy and indirect searches for Dark Matter. HERD features a 55X0, homogeneous, 3D segmented imaging calorimeter and can detect particles from the top and four lateral sides, providing precise energy measurements and electron/proton separation for a wide field of view. A key detector in HERD is the Silicon Charge Detector (SCD). SCD measures the charge of particles before interaction with other materials, minimizing cosmic rays nuclei fragmentation and reducing systematics on nuclei flux measurement. Thorough studies, TCAD and/or SPICE simulations, and accelerator tests on prototypes have been conducted to evaluate the tracking and charge resolution capabilities of the SCD. Further testing with 300 μm detectors is planned in the coming months to fully characterize the SCD's performance. This paper presents the results of the simulation studies and of the measured performance with particles.

Low-threshold 2 µm InAs/InP quantum dash lasers enabled by punctuated growth.

2 µm photonics and optoelectronics is promising for potential applications such as optical communications, LiDAR, and chemical sensing. While the research on 2 µm detectors is on the rise, the development of InP-based 2 µm gain materials with 0D nanostructures is rather stalled. Here, we demonstrate low-threshold, continuous wave lasing at 2 µm wavelength from InAs quantum dash/InP lasers enabled by punctuated growth of the quantum structure. We demonstrate low threshold current densities from the 7.1 µm width ridge-waveguide lasers, with values of 657, 1183, and 1944 A/cm2 under short pulse wave (SPW), quasi-continuous wave (QCW), and continuous wave operation. The lasers also exhibited good thermal stability, with a characteristic temperature T0 of 43 K under SPW mode. The lasing spectra is centered at 1.97 µm, coinciding with the ground-state emission observed from photoluminescence studies. We believe that the InAs quantum dash/InP lasers emitting near 2 µm will be a key enabling technology for 2 µm communication and sensing.

Cryo-X-ray phase contrast imaging enables whole biopsy imaging prior to multi-omic analysis

Abstract Background Analysis of myocardial biopsies using conventional two-dimensional (2D) histological techniques is limited in the detection of important three-dimensional (3D) structural features, such as disarray, due to sectioning and artefacts from dehydration or chemical processing. More advanced techniques such as light-sheet microscopy, micro-computed tomography or synchrotron radiation-based X-ray phase contrast imaging can provide non-destructive, 3D histological information at high resolution for formalin-fixed and/or paraffin-embedded (FFPE) biopsies. However, formalin fixation induces crosslinking of proteins which can impact quality and their subsequent analysis, for example, fragmentation of nucleic acids. A method for imaging 3D structure of myocardial biopsies in near-native state is needed which can then be followed by downstream multi-omic applications. Purpose To develop a technique called cryogenic X-ray phase contrast imaging (Cryo-X-PCI) to image snap-frozen myocardial biopsies at controlled low temperatures, followed by multi-omic analysis starting with analysis of DNA and RNA. Methods Myocardial biopsies (n=46) were obtained from C57BL/6 mice and snap-frozen in liquid nitrogen fresh or after 4% paraformaldehyde (PFA);10% formalin fixation. Pilot human aortic stenosis biopsies were also included (n=3, fresh). X-PCI was performed at -70°C using a cryojet, 20 keV beam energy and 0.65 µm detector pixel size (Figure 1). Datasets were reconstructed using Gridrec algorithm and Paganin phase retrieval. Morphologic analysis (myocardial disarray index, fractional anisotropy, helical angle, and intrusion angle) of biopsies was performed using a structure tensor-based approach via in-house MATLAB script. After imaging, DNA and RNA were extracted from murine biopsies followed by assessment of quantity and quality. Results Increased intercellular space between aggregates of myocytes was observed in all samples. This is consistent with reported findings in skeletal muscle using cryogenic conditions. Nonetheless, morphologic analysis of the biopsies proved possible (Figure 2). Optimal recovery of DNA and RNA was obtained from fresh frozen samples as compared to 4% PFA-fixed or 10% formalin-fixed samples. Conclusions This study demonstrates Cryo-X-PCI as a potential tool for analysing myocardial biopsies of heart muscle disease including morphologic analyses. Levels of DNA and RNA were not significantly affected indicating that downstream genomics, proteomics and transcriptomics analyses should be feasible.Setup for Cryo-X-PCI of frozen biopsiesMorphologic analysis of a biopsy

Effects of non-stationary blur on texture biomarkers of bone using Ultra-High Resolution CT.

To advance the development of radiomic models of bone quality using the recently introduced Ultra-High Resolution CT (UHR CT), we investigate inter-scan reproducibility of trabecular bone texture features to spatially-variant azimuthal and radial blurs associated with focal spot elongation and gantry rotation. The UHR CT system features 250×250 μm detector pixels and an x-ray source with a 0.4×0.5 mm focal spot. Visualization of details down to ~150 μm has been reported for this device. A cadaveric femur was imaged on UHR CT at three radial locations within the field-of-view: 0 cm (isocenter), 9 cm from the isocenter, and 18 cm from the isocenter; we expect the non-stationary blurs to worsen with increasing radial displacement. Gray level cooccurrence (GLCM) and gray level run length (GLRLM) texture features were extracted from 237 trabecular regions of interest (ROIs, 5 cm diameter) placed at corresponding locations in the femoral head in scans obtained at the different shifts. We evaluated concordance correlation coefficient (CCC) between texture features at 0 cm (reference) and at 9 cm and 18 cm. We also investigated whether the spatially-variant blurs affect K-means clustering of trabecular bone ROIs based on their texture features. The average CCCs (against the 0 cm reference) for GLCM and GLRM features were ~0.7 at 9 cm. At 18 cm, the average CCCs were reduced to ~0.17 for GLCM and ~0.26 for GLRM. The non-stationary blurs are incorporated in radiomic features of cancellous bone, leading to inconsistencies in clustering of trabecular ROIs between different radial locations: an intersection-over-union overlap of corresponding (most similar) clusters between 0 cm and 9 cm shift was >70%, but dropped to <60% for the majority of corresponding clusters between 0 cm and 18 cm shift. Non-stationary CT system blurs reduce inter-scan reproducibility of texture features of trabecular bone in UHR CT, especially for locations >15 cm from the isocenter. Radiomic models of bone quality derived from UHR CT measurements at isocenter might need to be revised before application in peripheral body sites such as the hips.

Low-Noise InGaAs/InP Single-Photon Avalanche Diodes for Fiber-Based and Free-Space Applications

We present the design and the experimental characterization of a new InGaAs/InP single-photon avalanche diode (SPAD), with two different diameters: i) a 10 μm device, suitable for optical fiber-based quantum applications; ii) a 25 μm one, more appropriate for free-space applications. Compared to a previous generation, we improved the design of the double zinc diffusion and optimized the layer structure. We achieved low dark count rate, around 1 kcps and 4 kcps at 225 K and 5 V excess bias for 10 μm and 25 μm devices, respectively, and down to few tens of counts per seconds at 175 K for the 10 μm detector. At 5 V excess bias and 225 K temperature, both devices also show a high photon detection efficiency (33% at 1064 nm, 31% at 1310 nm and 25% at 1550 nm for the 10 μm SPAD). Afterpulsing has been measured with a custom readout integrated circuit, achieving very low probability values. Timing jitter is comparable to previous-generation devices.

Study of charge carrier transport properties and lifetimes in HR GaAs:Cr with Timepix3

The response of a Timepix3 (256 × 256 pixels, pixel pitch 55 μm) detector with a 500 μm thick HR GaAs:Cr sensor was studied in proton beams of 125 MeV at the Danish Centre for Particle Therapy in Aarhus, Denmark and in a 120 GeV/c pion beam at the Super-Proton Synchrotron (SPS) at CERN. The sensor was biased at different voltages and irradiated at different angles. The readout chip was configured to operate in electron and hole collection modes. Measurements at grazing angles allowed to see elongated tracks with well-defined impact and exit points, so that charge carrier production depths could be determined in each pixel. We extracted the charge collection efficiencies and the charge carrier drift times as a function of the distance to the pixel plane. It was found that measured proton tracks are shorter in hole collection than in the case of electron collection, which is explained by the shorter lifetime of holes. At an angle of 60 degrees with respect to the sensor normal, the average track length in hole collection was ∼700 μm and 950 μm in electron collection mode. To understand the experimental findings, models describing the properties of HR GaAs:Cr were implemented into the Allpix2 simulation framework. We added previously presented experimental results describing the dependence of the electron drift velocity on the electric field and validated the response by comparing measurement and simulation for various X- and gamma-ray sources in the energy range of 10–60 keV. By comparison of the experimental and the simulated results, the mobility μ h and the lifetime of holes τ h were estimated as μ h = (320 ± 10) cm2/V/s and τ h = (4.5 ± 0.5) ns.

Single photon Lidar gas imagers for practical and widespread continuous methane monitoring

The accurate and comprehensive identification and quantification of greenhouse gas (GHG) emissions is an essential part of the management and mitigation of climate change. We are developing a novel remote gas imaging sensor for the detection, visualisation, and quantification of methane emissions. The sensor uses a new technique we call Tunable Diode Lidar (TDLidar) which combines aspects of Tunable Diode Laser Absorption Spectroscopy (TDLAS) with Differential Absorption Lidar (DIAL) and Time Correlated Single Photon Counting (TCSPC) to enable remote spectroscopy and ranging with low power semiconductor diode lasers. Our first TDLidar methane sensors use diode lasers with wavelengths around the CH4 absorption line at 1.6509 μm and Peltier-cooled Single Photon Avalanche Diode (SPAD) detectors in a Random Modulation Continuous Wave (RM-CW) Lidar system. Here we characterise our TDLidar methane sensor performance with calibrated gas cells and controlled gas release trials and we demonstrate quantification of leak rates as low as 0.012 g/s and detection at distances over 90 m. The accuracy, speed, and practicality of the sensor, combined with an expectation of low-cost in volume, offers the potential that these sensors can be effectively applied for widespread continuous and autonomous monitoring of industrial methane emissions.

Al0.6Ga0.4As x-ray avalanche photodiodes for spectroscopy

Two circular Al0.6Ga0.4As p+-i-n+ 2 µm i layer spectroscopic x-ray avalanche photodiodes (one 200 µm diameter and one 400 µm diameter) were made from a structure produced by metalorganic vapour phase epitaxy. The capacitances and currents of the detectors as functions of applied bias were measured, and 55Fe x-ray (Mn Kα = 5.9 keV; Mn Kβ = 6.49 keV) spectra were accumulated at 20 °C (293 K). Improved energy resolutions (measured as the full width at half maximum of the 5.9 keV peak) with increased applied reverse bias were observed with both detectors. In part, the improvement was attributed to avalanche multiplication. Energy resolutions of 630 eV ± 40 eV and 730 eV ± 50 eV were achieved with the 200 µm detector at an applied reverse bias of 38 V and the 400 µm detector at an applied reverse bias of 40 V, respectively. It is the first time Al0.6Ga0.4As has been demonstrated as capable of photon counting x-ray spectrometry. Measurements to determine the average electron-hole pair creation energy in Al0.6Ga0.4As were made; the results suggested a value of 4.97 eV ± 0.12 eV at 25 °C ± 1 °C (298 K ± 1 K). This value was then used to refine the apparent relationship between bandgap energy and electron-hole pair creation energy as defined by the Bertuccio–Maiocchi–Barnett relationship. AlxGa1-xAs x-ray photodiodes of this type are anticipated to be of benefit for future space missions, including those to explore the surfaces of the inner planets (e.g. Mercury and Venus) and the moons of Jupiter and Saturn.

High performance wide response GaAs based photo detector with nano texture on nanopillar arrays structure

Nanopillar arrays structure deployed over a top photodetector surface exhibits high light coupling efficiency which is attributed to their unique optical and structural properties. The paper presents a proposed GaAs material based periodic pyramidal cut nanopillar structure array model deployed over a 50 µm × 50 µm detector’s surface area. From the geometric analysis of the proposed model structure a maximum 99.8% light absorption has been achieved. Enhanced detector’s performance in terms of 0.75 A/W responsivity, as well as 56.8% external quantum efficiency for a narrow 0.5 µm depletion width, has also been demonstrated.

Improvements in electrical properties, low frequency noise and detection performance of a Mn-based bilayer thin film infrared detector

Experimental studies about low frequency 1/f noise and detection performance of Mn-based monolayer and bilayer structured detectors produced by Radio Frequency (RF) sputtering method have been carried out. Mn1.56Co0.96Ni0.48O4 (MCN) thick film (10 μm) was deposited on sapphire substrate to produce infrared detector by using sacrificial layer techniques. An MCN thin film (1 μm) detector and an Mn1.56Co0.96Ni0.48O4-Mn1.56Co0.80Cu0.16Ni0.48O4 (MCN-MCCN) bilayer thin film detector were also constructed by using wet chemical etching methods. The XRD results exhibited that the three samples all showed spinel structures. The varied temperature characters of the MCN and bilayer film samples were examined by voltage-current measurements ranging 250–320 K, and the characteristic temperature values were derived from the R-T curve. All three detectors showed similar temperature coefficient of resistance at about −3.5%K−1 at 295 K. The low frequency noise spectra of all three detectors were all conducted, where the bilayer film detector showed half the noise value than that of the MCN thin film sample. The detector fabricated by the MCN-MCCN bilayer film showed large response to 1550 nm laser radiation, as well as good thermal sensing ability to a blackbody. It is found that the response speed of the bilayer detector is one order faster than the MCN thick film detectors, where the time constant is about 0.17 ms. The detectivity of the MCN-MCCN detector was estimated to be on the order of 107 cm∙Hz0. 5/W. Simple considerations on bias voltage and thermal conductance G are given for further improvements by using the thermal isolation structures.

Small pitch resonator-QWIP detectors and arrays

We are developing small pixel 12-μm pitch resonator-QWIPs for infrared imaging at 8 μm and 10 μm. The materials and geometries are designed to yield 44% quantum efficiency (QE) at 1.0 × 1018 cm−3 doping and 56% at 1.2 × 1018 cm−3 for the 8 μm detectors and 47% at 1.0 × 1018 cm−3 for the 10 μm detector. Because of production variability and excess detector tunneling current at large bias, the maximum QE for the 8 μm detectors is measured to be 24.6% and 56.4%, respectively, while that for the 10 μm detector is 44%. Focal plane arrays of 1280 × 1024 resolution were produced from the lower doping, 8 μm material. Their performance is the same as the test detectors up to the maximum internal bias of the readout circuit. From the test detector I-V characteristics, the performance can be further projected to higher bias, at which the FPAs can offer 23 mK sensitivity at 3.7 ms integration time from the lower doping material and 21 mK at 3.2 ms from the higher doping material. For the 10 μm FPAs, the sensitivity is projected to be 30 mK at 3.8 ms. Therefore, we have demonstrated high sensitivity and fast R-QWIP FPAs down to 12-μm pitch. To expand the application envelope of the resonator-pixel technology, we have deigned resonant geometries for other infrared materials. Experimental efforts are underway.

High spatial resolution detection of low-energy electrons using an event-counting method, application to point projection microscopy.

An event-counting method using a two-microchannel plate stack in a low-energy electron point projection microscope is implemented. 15 μm detector spatial resolution, i.e., the distance between first-neighbor microchannels, is demonstrated. This leads to a 7 times better microscope resolution. Compared to previous work with neutrons [Tremsin et al., Nucl. Instrum. Methods Phys. Res., Sect. A 592, 374 (2008)], the large number of detection events achieved with electrons shows that the local response of the detector is mainly governed by the angle between the hexagonal structures of the two microchannel plates. Using this method in point projection microscopy offers the prospect of working with a greater source-object distance (350 nm instead of 50 nm), advancing toward atomic resolution.

单片集成的低暗电流1.3 μm激光二极管和探测器芯片

为了在单片上实现半导体激光二极管与探测器的集成，开展了外延材料生长及结构工艺的设计研究。通过刻蚀工艺引入隔离区的方法制备了集成背光探测器的1.3m InGaAsP/InP半导体激光二极管芯片。管芯的光电性能测试显示，激光二极管具有较低的阈值电流17.62 mA，较高的斜率效率0.13 mW/mA，输出功率可达11 mW；在-0.7 V的反向偏压下，探测器区域对光信号具有良好的线性响应，MPD的光电流超过0.3 mA，在-1.7 V的反向偏压下，暗电流可低至25 nA。

NBn HgCdTe infrared detector with HgTe(HgCdTe)/CdTe SLs barrier

Several strategies have been implemented to improve the performance of infrared single pixel detectors at higher operating temperature condition. The most efficient and effective in HgCdTe technology are: non-equilibrium architectures and currently an idea of the barrier detector to include unipolar and complementary structures. Valence band offset between active layer and barrier impeding the minority carrier transport is considered to be the most important issue to overcome. Currently, implementation of the Cd composition and doping graded interfaces has been proposed. In this paper we present the performance (dark current, detectivity, time response) of the nBn detector with HgTe(HgCdTe)/CdTe superlattice barrier. The superlattice barrier is believed to decrease valence band offset between active and barrier layers. Theoretically estimated detectivity of mid-wave (cut-off wavelength, 4.8 μm) detector is ~3×1012 cmHz1/2/W and time response 150 ps for zero valence band offset, bias 2 V and temperature 155 K.

Systematic study of Si-based GeSn photodiodes with 2.6 µm detector cutoff for short-wave infrared detection.

Normal-incidence Ge1-xSnx photodiode detectors with Sn compositions of 7 and 10% have been demonstrated. Such detectors were based on Ge/Ge1-xSnx/Ge double heterostructures grown directly on a Si substrate via a chemical vapor deposition system. A temperature-dependence study of these detectors was conducted using both electrical and optical characterizations from 300 to 77 K. Spectral response up to 2.6 µm was achieved for a 10% Sn device at room temperature. The peak responsivity and specific detectivity (D*) were measured to be 0.3 A/W and 4 × 109 cmHz1/2W-1 at 1.55 µm, respectively. The spectral D* of a 7% Sn device at 77 K was only one order-of-magnitude lower than that of an extended-InGaAs photodiode operating in the same wavelength range, indicating the promising future of GeSn-based photodetectors.

Carbon monoxide total columns from SCIAMACHY 2.3 µm atmospheric reflectance measurements: towards a full-mission data product (2003–2012)

Abstract. We present a full-mission data product of carbon monoxide (CO) vertical column densities using the 2310–2338 nm SCIAMACHY reflectance measurements over clear-sky land scenes for the period January 2003–April 2012. The retrieval employs the SICOR algorithm, which will be used for operational data processing of the Sentinel-5 Precursor mission. The retrieval approach infers simultaneously carbon monoxide, methane and water vapour column densities together with a Lambertian surface albedo from individual SCIAMACHY measurements employing a non-scattering radiative transfer model. To account for the radiometric instrument degradation including the formation of an ice-layer on the 2.3 µm detector array, we consider clear-sky measurements over the Sahara as a natural calibration target. For these specific measurements, we spectrally calibrate the SCIAMACHY measurements and determine a spectral radiometric offset and the width of the instrument spectral response function as a function of time for the entire operational phase of the mission. We show that the smoothing error of individual clear-sky CO retrievals is less than ±1 ppb and thus this error contribution does not need to be accounted for in the validation considering the much higher retrieval noise. The CO data product is validated against measurements of ground-based Fourier transform infrared spectrometers at 27 stations of the NDACC-IRWG and TCCON network and MOZAIC/IAGOS aircraft measurements at 26 airports worldwide. Overall, we find a good agreement with TCCON measurements with a mean bias b = −1.2 ppb and a station-to-station bias with σ = 7.2 ppb. The negative sign of the bias means a low bias of SCIAMACHY CO with respect to TCCON. For the NDACC-IRWG network, we obtain a larger mean station bias of b = −9.2 ppb with σ = 8.1 ppb and for the MOZAIC/IAGOS measurements we find b = −6.4 ppb with σ = 5.6 ppb. The SCIAMACHY data set is subject to a small but significant bias trend of 1.47 ± 0.25 ppb yr−1. After trend correction, the bias with respect to MOZAIC/IAGOS observation is 2.5 ppb, with respect to TCCON measurements it is −4.6 ppb and with respect to NDACC-IRWG measurements −8.4 ppb. Hence, a discrepancy of 3.8 ppb remains between the global biases with NDACC-IRWG and TCCON, which is confirmed by directly comparing NDACC-IRWG and TCCON measurements. Generally, the scatter of the individual SCIAMACHY CO retrievals is high and dominated by large measurement noise. Hence, for practical usage of the data set, averaging of individual retrievals is required. As an example, we show that monthly mean SCIAMACHY CO retrievals, averaged separately over Northern and Southern Africa, reflect the spatial and temporal variability of biomass burning events in agreement with the global chemical transport model TM5.

High-responsivity thermoelectric infrared detectors with stand-alone sub-micrometer polysilicon wires

A novel high-responsivity uncooled thermoelectric (TE) infrared (IR) detector is designed, fabricated and characterized. This detector features a single stand-alone polysilicon-based thermocouple (without a supporting membrane) covered by an umbrella-like optical cavity IR absorber. It is proved that the highest responsivity in the developed detectors can be achieved with only one thermocouple. Using a single thermocouple also results in a low resistance detector, which consequently limits the Johnson noise (e.g. less than 30 nv/√Hz in this work). Since the sub-micrometer polysilicon TE wires are the only heat path from the hot junction to the substrate, a superior thermal isolation is achieved. A responsivity of 1800 V W−1 and a detectivity of 2* 108 (cm Hz1/2 W−1) are measured from a 20 × 20 µm detector comparable to the performance of detectors used in commercial focal planar arrays []. This performance in a compact and manufacturable design elevates the position of thermoelectric IR sensors as a candidate for low-power, high performance and inexpensive focal planar arrays.

NIR Detector Nonlinearity and Quantum Efficiency

A study was performed to investigate the experimental conditions and systematic uncertainties that need to be considered in order to precisely characterize quantum efficiency (QE). Measurements were performed on a HAWAII-2RG1.7 μm detector but the methodology of characterization is applicable to other detectors as well and may be useful in characterization of detectors used in future ground and space based surveys. For this study the detector QE as a function of illumination intensity, total integrated signal, and temperature was measured. A 3% relative systematic uncertainty on the measured QE value was achieved at wavelengths longer than 800 nm but the total uncertainty in the determination of absolute QE is dominated by the uncertainty in the conversion gain, which adds an additional 3.4% scale uncertainty. It was found that the measured detector QE depends on illumination intensity and that temperature dependence of QE can, at least in part, be attributed to reciprocity failure. Well-chosen detector bias voltages can reduce integrated signal nonlinearity.

SU‐E‐I‐22: Performance Evaluation of a Commercial CMOS Detector for Dynamic High‐Resolution Imaging

Purpose: Present state‐of‐the art flat‐panel detectors have limitations in terms of noise and resolution for dynamic imaging. With recent developments, CMOS‐based detectors show promise to fulfill the ever increasing need for better image quality. Here, we evaluated a CMOS‐based detector by measuring its sensitivity, MTF, DQE and INEE. Methods: The detector (Hamamatsu Model # C10901D‐40) featured 12‐bit image acquisition, CsI phosphor, 100 μm detector pixel pitch and an active area of 9.7cm × 6.7cm and had a maximum frame rate of 30 fps. The sensitivity and instrumentation noise equivalent exposure (INEE) were calculated using flat‐field images taken at various exposures (4.2 μR to 334 μR). The detector resolution was evaluated by measuring the modulation transfer function (MTF) using a tilted edge. The noise power spectra (NPS) and detective quantum efficiency (DQE) were measured using the RQA5 spectrum for three different exposures (4.2 μR, 16.5 μR and 174 μR). Results: The signal vs. exposure curve showed excellent linearity of the detector and the sensitivity of the detector was found to be 5.8 DN/μR. The slope and the intercept of the variance vs. exposure curve were used to calculate the INEE of the detector, which was found to be 7.46 μR The measured MTF values were 0.61, 0.21 and 0.07 at 10%, 50% and 90% of the Nyquist frequency of 5 cycles/mm. The corresponding values of the DQE at these indicated frequencies were 0.47(0.56), 0.19(0.32) and 0.03(0.09) at 4.2 μR (16.5 μR). Conclusion: The imaging performance of Hamamatsu detector was evaluated in terms of sensitivity, linear system metrics and INEE. The INEE of this detector appears higher than desirable for fluoroscopy, but the detector shows good DQE at high exposure when the effect of the high instrumentation noise is not significant.(Support: NIH grants R01EB002873 and R01EB008425) NIH grants R01EB002873 and R01EB008425