From Deep UV to Mid-IR

An ITW CompanyPulsable High Speed Pire Infrared Emitter

SPF220-5M2

KEY FEATURES• Fast Pulsable Source of Black-body Radiation••••

Emulates a Black-body in Spectral Distribution
Ultra-thin Metallic Foil Active Element
Parabolic Reflector for Collimation and Uniformity
Fast Pulse Rates, up to 200 Hz with 50% Modulation Depth• High Output Emitter 0.04 Watts/cm2• Broadband Output with Typical 0.88 Emissivity• Hermetic Sapphire Window allowing Emission up to 6 um
APPLICATIONS• Gas Analysis, Medical and Industrial• Environmental Monitoring• Spectroscopy• Process Control Systems

The SPF IR emitter is designed to be used as fast pulsed sources of black-body radiation. The design has been
optimized for high modulation depth and optical output.
The radiating element in the pulsable emitter is an ultra-thin Opto Diode specific comb metallic foil configured sothat radiation from both sides of the heated foil is efficiently directed out of the package along the optic axis. The
foil material has a typical emissivity of 0.88 and closely emulates a black-body source in spectral distribution. Theemitter is designed to operate at a rated maximum foil temperature of 1000 Kelvin. The emitter is offered in ahermetically sealed TO-5 package with integral standard parabolic reflector to provide near collimated anduniform radiation output.

Revision September 24, 2019

Page 1 of 6

From Deep UV to Mid-IR

Pulsable High Speed Pire Infrared Emitter

An ITW Company

SPF220-5M2

Black-body Radiant EmittanceSPF Series emitters approximate black-body sources at their particular operating temperature. Below is areference graph showing ideal black-body curves at various temperatures, in K.
3.0(W cm-2 micron-1)

2.5
W500 (λ)
W750 (λ)
W1000 (λ)
W1170 (λ)

2.0
1.5
1.0
0.5
0.012345678910111213141516171819 20

λ (microns)

Filament Temperature vs. Input PowerThe SPF pulsable emitter is designed to operate with maximum element temperatures of approximately 1000 K(727°C) at the rated input power. Since the radiated energy is proportional to the fourth power of the absolutetemperature (T4) accurate control of the input power and proper heat sinking of the package are essential tomaintain consistent output. The heat sink must limit the package temperature to not more than 100°C. The
relationship between peak wavelength (λpk in microns) and temperature(T in Kelvin) for the black-body spectrum is expressed by Wien’s law:
λpk (microns) x T (K)= 2898
Thus, the wavelength for maximum excitation varies inversely with the absolute temperature. For 1000 K thismaximum is at 2.9 microns. The input pulse should have sufficient energy to produce a maximum filament
temperature of 1000 K.

Revision September 24, 2019Page 2 of 6

From Deep UV to Mid-IR

An ITW Company

Pulsable High Speed Pire Infrared Emitter

SPF220-5M2

Drive Circuit
Switching device like a single N-channel MOSFET with very low on-state resistance should be used. Basic
schematic is shown below.

Emitter Output Optimization
The power amplitude, pulse width, and frequency are adjusted to optimize the output of the emitter. The current
average current driving the source should not exceed and average current of 1 A otherwise the filament life will bedegraded. Below are scope shots of two different pulse widths. The frequency and pulse amplitude of the driverare held constant and the pulse width with only been adjusted. Channel 1 is the output of the emitter measured
with a PbSe detector and channel 2 is the emitter driver pulse REF monitor output from our Pire Plus Evaluation
Board and Kit that is available to evaluate this high-speed SPF SPF220-5M2 emitter. Note the differences inoutput amplitude between the narrow and wider pulse scopes. The narrower driver pulse gives less time for theelement to heat up, but it allows more time for it to cool off. The wider driver pulse gives more time for the element
to heat up and less time for it to cool off. The percentage modulation depth is lower with the wider pulse than thenarrower pulse, but the output intensity is much higher. This is because the element is heating up more with thewider pulse. This wider pulse makes the filament much hotter, increasing its output. In addition, the hotter filamentcools off much faster, which keeps a good modulation depth resulting in a higher output swing.

Revision September 24, 2019Page 3 of 6

From Deep UV to Mid-IR

An ITW Company

Pulsable High Speed Pire Infrared Emitter

SPF220-5M2

The narrower pulse width (channel 1 output of emitter, channel 2 driver pulse from Pire Plus Eval Board)
Note: that the intensity is lower but its percent modulation depth is higher.

The longer pulse width (channel 1 output of the emitter, channel 2 driver pulse from Pire Plus Eval Board)
Note: that the intensity is higher but its percent modulation depth is less.

Revision September 24, 2019

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From Deep UV to Mid-IRPulsable High Speed Pire Infrared Emitter

An ITW Company

SPF220-5M2

DC Power Curve (I vs V)1
2.5
Curve
SourceNo.
Model1SPF220-5M2

Amps

2.0

Pk DC
Power (watts)
2.78

1.5
1.0
0.5
0.0
0.0

0.5

1.0

1.5

2.0

2.5

3.0

Volts
11000 K at power indicted, exceeding this value will raise element temperature and decrease source lifetime.
Operating Temperature Range = –45° to +100°C.

Transmission (%)

Spectral Transmission of Window
10090807060
50403020
100100200

300

400

700

1000

2000

4000

8000

Wavelength (nm)株式会社 アイ・アール・システム〒206-0041 東京都多摩市愛宕4-6-20 IRSビル
電話:042-400-0373 FAX:042-400-0374
E-mail: office@irsystem.com Homepage: https://www.irsystem.com

Revision September 24, 2019

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From Deep UV to Mid-IR

An ITW Company

Pulsable High Speed Pire Infrared Emitter

SPF220-5M2Package Dimensions

Heatsink Dimensions

Ordering Information
High Speed Emitter in TO5 Package with Sapphire Window Model Number: SPF220-5M2 (P/N 40101)
High Speed Emitter with Heatsink Model Number: SPF220-5M2H (P/N 40800)
Evaluation Board with emitter Kit Model Number: PIREPLUS (P/N 40801)(Kit includes a SPF220-5M2 Emitter and heatsink)Specifications are subject to change without prior notice.

1260 Calle Suerte, Camarillo, California 93012
Phone: +1 805.499.0335 | Fax: +1 805.499.8108 | sales@optodiode.com | www.optodiode.com
Revision September 24, 2019

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