Quantum cascade lasers (QCLs) and Interband cascade lasers (ICLs) are promising new mid-IR sources for spectroscopic
applications. Desirable characteristics include extremely high brightness, broad emission, very high resolution, compact
size, and modest power consumption. For most spectroscopic applications, it is necessary to tune QCLs over a broad
emission wavelength range. The conventional approach for broad tuning is to use an external cavity (EC) which
incorporates a mechanically tuned diffraction grating within the laser cavity.
In this paper we will describe an alternative approach to EC-QCL tuning which utilizes miniature, thermally tuned, MEMS
fabricated filters, allowing for a very compact, simple, mechanically stable package with no moving parts. The system
is well suited for discrete measurements at multiple wavelengths as needed by many of the industrial spectroscopic
analyzers in use today. An accuracy of 0.02 cm-1 over the 50 cm-1 range of the test laser and a precision of 0.002 cm-1 over
a 15 cm-1 scan has been demonstrated. High resolution mode hop free CW scanning of a 0.5 cm-1 range at a scan rate of
200 Hz with a wavelength precision of 0.002 cm-1 has also been demonstrated. This makes the design an attractive
alternative to current Distributed feedback (DFB) QCLs for high resolution gas phase measurements due to the added
advantage of broad tunability for the detection of multiple gases, and the capability to select multiple gas lines of different
intensity to extend the dynamic range.
Lockheed Martin IR Imaging Systems is developing low cost, high performance, uncooled IR imaging products for both military and commercial applications. These products are based on microbolometer technology, a silicon micromachined sensor that combines wafer level silicon processing with a device structure capable of yielding excellent imaging performance. Here, in the third of a series of papers, we report on several applications that are utilizing the Lockheed Martin microbolometer sensor. The performance of our basic uncooled sensor has been measured to determine sensor capabilities for insertion into both military and commercial products. Non-linearity of the sensor over a scene temperature range of 95 degrees C is less than 0.5 percent. Our sensor typically have temporal NETDs of less than 70 mK as well as spatial NETDs of less than 50 mK, with an instantaneous dynamic range of 84 dB, and a total dynamic range of 120 dB. MRTD performance is less than 0.4 degrees C at spatial frequencies more than 20 percent beyond Nyquist. Spatial noise variation over time has been measured and found to meet both commercial and military requirements with excellent spatial noise over wide scene and ambient temperature ranges. Some of the multiple applications in which our uncooled sensor have been used have been described in reports demonstrating the varied and unique uses of this product. Our sensor is now used by dozens of partners and customers for applications ranging from hand-held radiometric camera to driving aids; from long range surveillance cameras to miniature cameras; from rifle sights to helmet mounted camera. These applications will be discussed along with their unique system level performance parameters. Video will be used to demonstrate the various applications discussed.
Lockheed Martin IR Imaging Systems is developing low cost, high performance, uncooled infrared imaging products for both military and commercial applications. These products are based on microbolometer technology, a silicon micromachined sensor that combines wafer level silicon processing with a device structure capable of yielding excellent imaging performance. Here, in the first of a series of papers, we report on several applications that are utilizing the Lockheed Martin microbolometer sensor. The performance of our basic uncooled sensor has been measured (and reported in multiple papers) to determine sensor capabilities for insertion into both military and commercial products. Non-linearity of the sensor over a scene temperature range of 95 degrees Celsius is less than 0.5%. Our sensors typically have temporal NETDs of less than 70 mK as well as spatial NETDs of less than 50 mK. MRTD performance is less than 0.4 degrees Celsius at spatial frequencies more than 20% beyond Nyquist. Spatial noise variation over time has been measured and found to meet both commercial and military requirements with excellent spatial noise over wide scene and ambient temperature ranges. Some of the multiple applications in which our uncooled sensors have been used have just recently been described in one report demonstrating the varied and unique uses of this product. Our sensor is now used by dozens of partners and customers for applications ranging from hand-held radiometric cameras to driving aids; from driver's aids to miniature cameras from rifle sights to radiometers. These applications will be discussed along with their unique system level performance parameters. Video will be used to demonstrate the various applications discussed.
Lockheed Martin IR Imaging Systems is developing low cost, high performance, uncooled infrared imaging products for both military and commercial applications. These products are based on microbolometer technology, a silicon micromachined sensor that combines wafer level silicon processing with a device structure capable of yielding excellent imaging performance. Here, in the first of a series of papers, we report on several applications that are utilizing the Lockheed Martin microbolometer sensor. The performance of our basic uncooled sensor has been measured (and reported in multiple papers) to determine sensor capabilities for insertion into both military and commercial products. Non-linearity of the sensor over a scene temperature range of 95 degrees Celsius is less than 0.5%. Our sensors typically have temporal NETDs of less than 70 mK as well as spatial NETDs of less than 50 mK. MRTD performance is less than 0.4 degrees Celsius at spatial frequencies more than 20% beyond Nyquist. Spatial noise variation over time has been measured and found to meet both commercial and military requirements with excellent spatial noise over wide scene and ambient temperature ranges. However, the multiple applications in which our uncooled sensors have been used have never been described in one report demonstrating the varied and unique uses of this product. Our sensor is now used by dozens of partners and customers for applications ranging from hand-held radiometric cameras to driving aids; from sniper location prototype cameras to helmet mounted mine detection sensors; from rifle sights to space sensors. These applications will be discussed along with their unique system level performance parameters. Video will be used to demonstrate the various applications discussed.
Lockheed Martin IR Imaging Systems is developing low cost, high performance, uncooled infrared imaging products for both military and commercial applications. These products are based on the microbolometer technology, a silicon micromachined sensor that combines wafer level silicon processing with a device structure capable of yielding excellent imaging performance. Here we report on the latest technical improvements and performance of an uncooled sensor as measured through laboratory and field testing. The performance of our uncooled sensor has been measured to determine sensor capabilities for insertion into both military and commercial products. Linearity of the sensor over a scene temperature range of 95 degrees Celsius is less than 0.5%. Our sensors typically have temporal NETDs of less than 70 mK as well as spatial NETDs of less than 50 mK. MRTD performance is less than 0.4 degrees Celsius at spatial frequencies more than 20% beyond Nyquist. Sensor stability over time has been measured and found to meet both commercial and military requirements. Spatial noise over a wide scene temperature range is reported as well as other test results. Video is used to demonstrate sensor performance capabilities in a variety of applications.
Uncooled infrared imaging technology provides a new, affordable, high performance tool for both conventional and emerging applications in the surveillance and law enforcement markets. This technology offers users significant advantages, including high reliability, low power consumption, excellent image clarity, and good performance in adverse environments. This paper briefly discusses the various technologies used for night imaging, the advantages that infrared systems offer law enforcement and surveillance applications, how uncooled infrared systems fit into this market, and the status of uncooled microbolometer systems at Lockheed Martin.
Loral Infrared & Imaging Systems is developing low cost, high performance, uncooled infrared imaging products for both military and commercial applications. These products are based on the microbolometer technology, a silicon micromachined sensor which combines the wafer level silicon processing with a device structure capable of yielding excellent infrared imaging performance. Here, we report on the development of an uncooled sensor, the LTC500, which incorporates an all digital focal plane array and has a measured NETD of less than 70 mK. The focal plane array and the electronics within the LTC500 have been designed as an integrated unit to meet a broad range of end user applications by providing features such as nonuniformity correction, autogain and level, NTSC video, and digital outputs. The 327 X 245 element focal plane array has a 46.25 micrometers pixel pitch and an on focal plane array 14 bit to analog to digital converter (ADC). The ADC has a measured instantaneous dynamic range of more than 76 dB at a 6.1 MHz output data rate and 60 Hz frame rate. The focal plane array consumes less than 500 mW of power, of which less than 250 mW is used in the ADC. An additional 36 dB of digital coarse offset correction in front of the ADC on the focal plane array results in a total electronic dynamic range of 112 dB. The MRT of the LTC500 camera has been measured at less 0.2 C at fo.
Loral Infrared & Imaging Systems is developing low cost, high performance uncooled infrared imaging products for both military and commercial applications. These products are based on the microbolometer technology, a silicon micromachined sensor which combines the wafer level silicon processing with a device structure capable of yielding NETD performance of better than 40 mK. To achieve a low cost sensor, Loral is proceeding with an integrated approach to the design and manufacturing processes associated with each major element of the uncooled sensor: focal plane array, electronics, optics and housings. Loral's 327 by 245 focal plane array has a 46.25 micrometer pixel pitch and incorporates a CMOS readout integrated circuit (ROIC). The ROIC has been designed to greatly simplify the external electronics, and features a single output which can operate at both 60 Hz (NTSC) and 50 Hz (PAL) video rates. The sensor electronics have been designed to meet a broad range of end user applications by providing both analog video and digital outputs with a large selection of user definable options and operating modes. To achieve low manufacturing costs across multiple end user applications, common optical interfaces, structural components, and manufacturing processes are being utilized. Sensor NETD is projected to be 40 mK normalized to f/1 and a 30 Hz frame rate. MRT is projected to be better than 0.1 degree Celsius at f0.
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