Development Of Focal Plane Arrays Research Articles

Group II–VI semiconductor quantum dot heterojunction photodiode for mid wave infrared detection

In this article we report the development of 10×10 photodiode array by realizing heterojunction between mercury cadmium telluride (HgCdTe) quantum dot (diameter ∼14 nm) and silicon responsive in mid wave infrared (MWIR) range (λ=3–5 µm) at room temperature. Performance of this optical sensor has been evaluated experimentally and Detectivity of $$1.6 \times {10^8}{\rm{cm}}\sqrt {{\rm{Hz}}} /{\rm{W}}$$ has been achieved at spectral wavelength of 3.5 µm at 300 K. This work ascertains the compatibility of chemically synthesized HgCdTe quantum dots with commercially available direct injection type readout integrated circuits (ROIC) for the development of low cost large format MWIR focal plane array (FPA).

On-Orbit Signal-to-Noise Ratio Test Method for Night-Light Camera in Luojia 1-01 Satellite Based on Time-Sequence Imagery.

Night-light remote sensing imaging technologies have increasingly attracted attention with the development and application of focal plane arrays. On-orbit signal-to-noise ratio (SNR) test is an important link to evaluate night-light camera’s radiometric performance and the premise for quantitative application of remote sensing imageries. Under night-light illumination conditions, the illuminance of ground objects is very low and varies dramatically, the spatial uniformity of each pixel’s output cannot be guaranteed, and thus the traditional on-orbit test methods represented by variance method are unsuitable for low-resolution night-light cameras. To solve this problem, we proposed an effective on-orbit SNR test method based on consecutive time-sequence images that including the same objects. We analyzed the radiative transfer process between night-light camera and objects, and established a theoretical SNR model based on analysis of the generation and main sources of signal electrons and noise electrons. Finally, we took Luojia 1-01 satellite, the world’s first professional night-light remote sensing satellite, as reference and calculated the theoretical SNR and actual on-orbit SNR using consecutive images captured by Luojia 1-01 satellite. The actual results show the similar characteristics as theoretical results, and are higher than the theoretical results within the reasonable error tolerance, which fully guarantee the detection ability of night-light camera and verify the validity of this time-sequence-based method.

微型近红外物联网节点的传感器输出数字化应用研究

The rise of the Internet of Things (IOT) spectral analysis technology has driven the development of near infrared spectroscopy sensors toward miniaturization, digitization and intelligence. A specific digitization research on InGaAs spectral sensor was reported to meet the digital and intelligent development of InGaAs focal plane Arrays (FPA). A new compact near infrared spectral node was developed integratedly with digital output spectral sensor circuit using self-developed analog to digital convertor (ADC) chip. The proposed node integrated 202 effective spectral channels with a wavelength range of 900 nm to 1 700 nm and a spectral resolution better than 16 nm. The wavelength accuracy and repeatability was less than 1 nm and 0.3 nm, respectively. The signal to noise ratio (SNR) of node system was about 500:1, and the frame scanning time was about 3 ms. The research results show that the compact IOT spectral node meets the practical application requirements of near infrared spectral analysis, and provides technical supports for the sensor on-chip digitization and IOT near infrared spectral analysis applications.

Integration and fabrication of high-performance Sb-based heterostructure backward diodes with submicron-scale airbridges for terahertz detection

In this work, the authors report integration and fabrication of high-performance Sb-based heterostructure backward diodes (HBDs) with planar folded dipole antennas (FDAs) using submicron-scale airbridges for terahertz (THz) detection. By integrating HBDs into FDAs, high detector responsivity of 20 000 V/W at 200 GHz and 9500 V/W at 585 GHz could be potentially achieved due to the optimized impedance matching between the antenna and HBD detector. In order to minimize interconnect parasitics, the HBD integration is accomplished using submicron-scale airbridges. Electromagnetic simulations coupled to device models show that by introducing submicron-scale airbridges and optimizing the device layout, parasitic capacitance and spreading resistance can be significantly reduced. This allows performance nearly equal to the intrinsic device performance to be obtained. To achieve this level of performance, a novel fabrication and integration process has been developed. The process includes mix-and-match electron beam and optical lithography to span the size scales required for both the FDA and small-area HBDs, and offers high accuracy and reproducibility while requiring fewer critical fabrication steps compared to conventional hybrid integration techniques. Devices fabricated using this process have obtained a record-high device curvature coefficient of −58 V−1, indicating the quality of the devices that can be achieved. The process is scalable—in terms of device size, frequency range, and array size—enabling the development of THz focal plane arrays in a wide frequency range (100 GHz to beyond 1 THz).

Recent Developments in Mercury Cadmium Telluride IR Detector Technology

In spite of many attempts to find better material for infrared detectors, HgCdTe still dominates the high performance end of the market. At present, the research in this field is directed towards high pixel density, high yield, reduced cooling and hyperspectral operation. Long lasting issue of availability of high quality, large area substrates for epitaxial growth of HgCdTe seems to be easing recently with development of 4” CdZnTe lattice matching substrates reported recently. The quality of HgCdTe grown on alternative substrates like silicon, GaAs or recently investigated GaSb still falls behind that achievable on CdZnTe due to large lattice mismatch leading to high defect density. Recent effort to scale down the pixel size and pitch resulted in development of diffraction limited high definition focal plane arrays. Implementation of unipolar n-type/barrier/n-type detector structure in HgCdTe material system has been recently proposed and studied intensively. Due to superior transport and optical properties of HgCdTe it is expected that, when optimized, these structures will allow for background limited performance at significantly higher operating temperatures.

Low-Cost Millimeter Wave Imaging Using a Commercial Plasma Display

The use of glow discharge detectors to detect millimeter wave radiation is well documented and work is starting of the development of focal plane arrays to produce 2D images. This paper demonstrates the feasibility of using a low-cost commercial plasma display as an imager in the millimeter wave band. It shows that though the performance is not as good as that for individual glow discharge detectors, it is sufficiently good for short range imaging. This paper goes on to propose extending the modality to provide 3D images in near real time using each element of the array as a mixer in a frequency modulated continuous wave radar.

In(AsN) mid-infrared emission enhanced by rapid thermal annealing

We report a substantial increase in the quality and photoluminescence (PL) emission efficiency of In(AsN) dilute nitride alloys grown on both p-type InAs and semi-insulting GaAs substrates, in response to rapid thermal annealing. At 4K the PL emission efficiency increases by 25 times due to a reduction in non-radiative Shockley–Read–Hall recombination originating from elimination of point defects. For annealing temperatures up to 500°C the activation energy for thermal quenching increases by a factor of three, with no change in the residual electron concentration and mobility. Temperature dependent PL, together with X-ray diffraction measurements, reveals an improvement in compositional uniformity. Our results are significant for photonic device applications and particularly for the development of cryogenic mid-infrared photodiodes, monolithic detectors and focal plane arrays.

Advances in Fourier transform infrared spectroscopy of natural glasses: From sample preparation to data analysis

Fourier transform infrared spectroscopy (FTIR) is an analytical technique utilized to measure the concentrations of H and C species in volcanic glasses. Water and CO2 are the most abundant volatile species in volcanic systems. Water is present in magmas in higher concentrations than CO2 and is also more soluble at lower pressures, and, therefore it is the dominant volatile forming bubbles during volcanic eruptions. Dissolved water affects both phase equilibria and melt physical properties such as density and viscosity, therefore, water is important for understanding magmatic processes. Additionally, quantitative measurements of different volatile species using FTIR can be achieved at high spatial resolution. Recent developments in analytical equipment such as synchrotron light sources and the development of focal plane array (FPA) detectors allow higher resolution measurements and the acquisition of concentration maps. These new capabilities are being used to characterize spatial gradients (or lack thereof) around bubbles and other textural features, which in turn lead to new insights into the behavior of volcanic feeder systems. Here, practical insights about sample preparation and analysis of the distribution and speciation of volatiles in volcanic glasses using FTIR spectroscopy are discussed. New advances in the field of FTIR analysis produce reliable data at high spatial resolution that can be used to produce datasets on the distribution, dissolution and diffusion of volatiles in volcanic materials.

Development of quantum well, quantum dot, and type II superlattice infrared photodetectors

We present an overview of III-V semiconductor-based infrared detector and focal plane array development at the NASA Jet Propulsion Laboratory in recent years. Topics discussed include: (1) the development of long-wavelength quantum well infrared photodetector for imaging spectrometer applications, (2) the concept and realization of the submonolayer quantum dot infrared photodetector (SML-QDIP) as an alternative to the standard QDIP-based on Stranski-Krastanov (SK) quantum dots, (3) the mid-wavelength infrared quantum dot barrier infrared detector with extended cutoff wavelength, and (4) high-performance type-II superlattice long-wavelength infrared detectors based on the complementary barrier infrared detector architecture.

Theoretical modeling of InAsSb/AlAsSb barrier detectors for higher-operation-temperature conditions

InAsSb is considered as an alternative to HgCdTe ternary alloy as far as infrared (IR) detection systems are concerned. Lately, there has been an enormous progress in the development of InAsSb focal plane arrays. High-operating-temperature conditions were successfully achieved with A III B V unipolar barrier structures including InAsSb/AlAsSb and InAs/AlAsSb material systems. The performance of medium-wavelength IR InAsSb-based nB n nn + detectors is examined theoretically. Since there is no depletion layer in the active layer of such devices, the generation-recombination and trap-assisted tunneling mechanisms are suppressed, leading to lower dark currents in bariode detectors in comparison with standard diodes. Detailed analysis of the detector performance (such as dark current, dynamic resistance area product, and detectivity) versus bias voltage and operating temperatures are performed by pointing out optimal working conditions. The theoretical predictions of bariode parameters are compared with experimental data published in the literature. Finally, the bariode performance is compared with standard InAsSb photodiodes operated at room temperature.

High performance long-wave type-II superlattice infrared detectors

The authors report on growth, material characterization, and device performance of infrared photodetectors based on type II InAs/GaSb superlattices using the complementary barrier infrared detector (CBIRD) design. In this paper, control steps for improvement of material quality in terms of surface, structural, and optical properties of infrared detectors grown at Jet Propulsion Laboratory are described. For a specific CBIRD studied, these quality control steps indicate high structural and optical quality of the grown material. Furthermore, single-element detector from the optimized growth conditions exhibit dark current density less than 1 × 10−5 A/cm2 at applied biases up to Vb = 0.36 V (T = 77 K), so this material can be utilized for focal plane arrays development.

THz Scanner Based on Planar Antenna-Supplied Silicon Field-Effect Transistors

A scanning device for imaging at THz frequencies was designed and constructed. The device comprised a 335~GHz source of radiation, an x-y-z translation stages, a number of optical elements and a detector. The detector was a silicon field-effect transistor supplied with a resonant antenna and a low-noise preamplifier. With a detector response of 10~V/W and a source power of 10~mW we could generate images in a DC mode with a speed limited only by the velocity of the stages movement. Full Text: PDF References W. Knap et al. "Plasma wave detection of sub-terahertz and terahertz radiation by silicon field-effect transistors", Appl. Phys. Lett. 85, 675 (2004). CrossRef R. Tauk et al. "Plasma wave detection of terahertz radiation by silicon field effects transistors: Responsivity and noise equivalent power", Appl. Phys. Lett. 89, 253511 (2006). CrossRef N. Oda et al. "Development of Terahertz focal plane arrays and handy camera", Proc. SPIE 8012 CrossRef E. Ojefors, U. Pfeiffer, A. Lisauskas, and H. Roskos, "A 0.65 THz Focal-Plane Array in a Quarter-Micron CMOS Process Technology", IEEE J. Solid-state Circuits 44, 1968 (2009). CrossRef M. Dyakonov and M. Shur, "Detection, mixing, and frequency multiplication of terahertz radiation by two-dimensional electronic fluid", IEEE Trans. on Electron Devices 43, 380 (1996). CrossRef P. Kopyt, J. Marczewski, K. Kucharski, J. Łusakowski, and W. Gwarek, "Planar antennas for THz radiation detector based on a MOSFET ", Proc. 36th Conference on Infrared, Millimeter and Terahertz Waves, Huston, CrossRef M. Sakowicz et al. "Terahertz responsivity of field effect transistors versus their static channel conductivity and loading effects", J. Appl. Phys. 110, 054512 (2011). CrossRef

A Novel Broadband Q-Band Polarizer with Very Flat Phase Response

We present a 33–50 GHz circular waveguide polarizer based on a broadband combination of retarders. The device was designed within the FP7 RadioNet APRICOT (‘All Purpose Radio Imaging Cameras on Telescopes’) consortium for the development of focal plane arrays for radiotelescopes. The device is based on a Pancharatnam recipe used in optics and behaves as a polarization transformer, from circular to linear and vice versa. This novel design of polarizer exhibits an unprecedented performance combining extremely flat differential phaseshift across the whole band, very low losses and very low Amplitude Unbalance (AU). It can be used in astronomical instruments or telecommunication antennas where very high purity circular polarization is required. The design was manufactured and then tested using a Vector Network Analyzer (VNA). Averaged across a 40% bandwidth the measured RL, IL, amplitude unbalance and differential phase-shift were respectively:−31.4/−35.3 dB, −0.09/−0.06 dB, 0.04 dB and 90.0 ± 0.4°.

Inexpensive THz Focal Plane Array Imaging Using Miniature Neon Indicator Lamps as Detectors

Development of focal plane arrays (FPAs) for mm wavelength and THz radiation is presented in this paper. The FPA is based upon inexpensive neon indicator lamp Glow Discharge Detectors (GDDs) that serve as pixels in the FPA. It was shown in previous investigations that inexpensive neon indicator lamp GDDs are quite sensitive to mm wavelength and THz radiation. The diameters of GDD lamps are typically 3-6 mm and thus the FPA can be diffraction limited. Development of an FPA using such devices as detectors is advantageous since the costs of such a lamp is around 30-50 cents per lamp, and it is a room temperature detector sufficiently fast for video frame rates. Recently, a new 8 × 8 GDD FPA VLSI control board was designed, constructed, and experimentally tested. First, THz images using this GDD FPA are given in this paper. By moving around the 8 × 8 pixel board appropriately in the image plane, 32 × 32 pixel images are also obtained and shown here, with much improved image quality because of much reduced pixelization distortion.

Deposition and Characterization of Pyroelectric PMN-PT Thin Films for Uncooled Infrared Focal Plane Arrays

Modern uncooled infrared focal plane arrays (UFPA) development is oriented toward silicon microstructure monolithic arrays by employing pyroelectric thin films with continuing trends in high performance and miniaturization. In order to exploit high performance pyroelectric thin films, (1−x)Pb(Mg1/3Nb2/3)O3−xPbTiO3(PMN-PT) thin films withx= 0.26 were deposited on LaNiO3/Si substrates by the radio-frequency magnetron sputtering technique. (110) preferred orientation thin films with pure perovskite structures were obtained at a substrate temperature of 500°C. The ferroelectric, dielectric and pyroelectric properties of the films were investigated. The films show a typical polarization – electric filed hysteresis loop with a large remnant polarization of 17.2 μC/cm2. At room temperature, the high pyroelectric coefficient of 3.1 × 10-4C/m2K together with low dielectric constant of 470 and loss tangent of 0.04 render the film promising for uncooled infrared device applications. The origin of the differences in electrical properties between the films and bulk materials has also been discussed.

Recent development of 3D focal plane arrays

Laser radars have traditionally employed beam scanning and sequential range interrogation in order to generate three-dimensional (3D) images. Pulsed modulation is commonly used in order to measure range. The image size and image rate of 3D or range imaging laser radars are frequently limited by the pulse repetition rate and by scanner efficiency. Increases in the pulse repetition may increase frame size and frame rate, but only at the expense of increased range ambiguity and increased complexity of the scanner and transmitter. Staring arrays that incorporate time of arrival measurements have recently become available. These arrays have the potential of simplifying instrument design while increasing image size and image rate without increasing range ambiguity. In our work, we discuss most sensitive aspects of ladar design using focal plane arrays

Terahertz detectors and focal plane arrays

AbstractTerahertz (THz) technology is one of emerging technologies that will change our life. A lot of attractive applications in security, medicine, biology, astronomy, and non-destructive materials testing have been demonstrated already. However, the realization of THz emitters and receivers is a challenge because the frequencies are too high for conventional electronics and the photon energies are too small for classical optics. As a result, THz radiation is resistant to the techniques commonly employed in these well established neighbouring bands.In the paper, issues associated with the development and exploitation of THz radiation detectors and focal plane arrays are discussed. Historical impressive progress in THz detector sensitivity in a period of more than half century is analyzed. More attention is put on the basic physical phenomena and the recent progress in both direct and heterodyne detectors. After short description of general classification of THz detectors, more details concern Schottky barrier diodes, pair braking detectors, hot electron mixers and field-effect transistor detectors, where links between THz devices and modern technologies such as micromachining are underlined. Also, the operational conditions of THz detectors and their upper performance limits are reviewed. Finally, recent advances in novel nanoelectronic materials and technologies are described. It is expected that applications of nanoscale materials and devices will open the door for further performance improvement in THz detectors.

InAs/GaSb superlattices for advanced infrared focal plane arrays

We report on the development of high performance focal plane arrays for the mid-wavelength infrared spectral range from 3–5 μm (MWIR) on the basis of InAs/GaSb superlattice photodiodes. An investigation on the minority electron diffusion length with a set of six sample ranging from 190 to 1000 superlattice periods confirms that InAs/GaSb superlattice focal plane arrays achieve very high external quantum efficiency. This enabled the fabrication of a range of monospectral MWIR imagers with high spatial and excellent thermal resolution at short integration times. Furthermore, novel dual-color imagers have been developed, which offer advanced functionality due to a simultaneous, pixel-registered detection of two separate spectral channels in the MWIR.

Low temperature growth and laser-induced phase transformation of perovskite oxide films for uncooled IR detector applications

AbstractPyroelectric infrared (IR) detectors based on perovskite oxides are of interest in part because of their lack of need for cooling, which makes them relatively more affordable and operationally simpler than cooled photon detector systems. We are investigating two methods for low-cost growth of perovskite oxide thin films, namely, a bio-inspired, low-temperature synthesis method and a modified industry-standard metalorganic solution deposition (MOSD) method. Subsequent to film synthesis, we utilize direct-write laser phase conversion and micro-electro-mechanical systems (MEMS) fabrication for development of an uncooled IR focal plane array (FPA). Film growth, crystallization and MEMS processes are compatible with monolithic integration of the detector pixels directly onto Si readout integrated circuits (ROICs).

Design of inexpensive diffraction limited focal plane arrays for millimeter wavelength and terahertz radiation using glow discharge detector pixels

Development of focal plane arrays (FPAs) for millimeter wavelength and terahertz radiation is presented in this paper. FPA is based on an inexpensive glow discharge detector (GDD) that serves as a pixel in the FPA. It was shown in previous investigations [A. Abramovich et al., Appl. Opt. 46, 7207 (2007)] that those inexpensive neon indicator lamp GDDs are quite sensitive to millimeter wavelength and terahertz radiation. The diameter of the GDD lamp is 6 mm and thus the FPA can be diffraction limited. Development of a FPA using such devices as detectors is advantageous since the cost of such lamps is around $0.2–0.5 per lamp, and it also serves as a room temperature detector. Experimental results at 100 GHz show that the responsivity of the terahertz FPA 4×4 GDD pixel is three times better than in previous measurements of A. Abramovich et al. [Appl. Opt. 46, 7207 (2007)].The addition of a parabolic reflector improves the accuracy of the noise equivalent power measurement which was found to be 6×10−9 W/√Hz for a 1 kHz modulation. However, it is expected to be considerably less at higher modulation frequencies because of much reduced noise.