Infrared Radiators

Ion Optics offers a new class of electrically-pulsed, high intensity infrared radiators for gas analysis, spectroscopy and calibration. These radiators feature a low pulsIR Downloads/LightSourceDataSheet2-00.PDF pulsIR Downloads/LightSourceDataSheet2-00.PDFthermal-mass filament tailored for high emissivity in either the MWIR (2-5 um) or the LWIR (8-12um). Efficient in-band emission permits operation at temperatures several times cooler than tungsten bulbs and gives a radiator life of many years. This patent-pending, high-efficiency device minimizes drive power, greatly reducing parasitic heating of detectors and optics; it also eliminates the mechanical choppers permitting a sealed optical path.

• Broadband IR Light from 2 - 20 µm
  
• Pulsed or DC operation
  
• Large Temperature modulation in pulsed mode
  
• Many Package and window options
  
• Available Evaluation Kit for rapid demonstration in your system

The Evaluation Kit is designed to allow convenient experimentation with Ion Optics' family of infrared sources. The Evaluation Kit consists of: (a) a PC-controlled drive board producing a flat-topped current pulse of adjustable amplitude, length, and frequency; (b) Windows compatible software; and (c) the IR light source of your choosing. The kit can be run using dip selectable pre-programmed settings, or connected to a PC for user selection of temperature, pulse rate, and duty cycle.

The emissivity of these metal filament infrared sources is enhanced and controlled by creating random surface texture (sub-micron scale rods and cones), as shown in the Figure. This texture modifies the reflection and absorption spectra relative to that for a flat filament of the same material. For wavelengths small compared to the feature sizes, the surface scatters most incoming light, therefore it has low reflectivity (the filaments appear visibly black), and by Kirchoff's law, it must also have high emissivity (>80%). For wavelengths long compared to the feature sizes, the surface still looks like flat metal and it therefore has low emissivity, characteristic of the flat metal (£ 0.1).

The high emissivity of the ion-beam-treated radiator surface enables it to efficiently and rapidly cool via thermal radiation. The infrared image below (left pair) show an Ion Optics source being electrically pulsed; the hot filament (left image) nearly cools to background temperature (right image) before the next pulse, thus providing several hundred degrees of temperature modulation. While the image pair on the right shows a traditional light source which must be run many times hotter than the Ion Optics source. The package heats up considerably and the apparent IR temperature difference in each pulse becomes only a few degrees.

• Large temperature modulation
  
• No chopper required
  
• Superior LWIR Power
  
• High Signal-to-noise ratio
  
• Shot-to-shot repeatability
  
• Long term stability

Ion Optics, Inc., 411 Waverley Oaks Road, Suite 144, Waltham, MA 02452. Tel: 781-788-8777; Fax: 781-788-8811.