Opto Diode’s SA Series and SHA Series are steady-state (DC) infrared emitters built around a coiled filament with a specialized coating, radiating a spectrum that closely emulates a black-body source. Both series operate at a rated filament temperature of 1170 K, which places peak output near 2.5 µm, and both are manufactured by Opto Diode, a division of ITW, in Camarillo, California. The specifications on this page come from the SA Series and SHA Series datasheets, both Revision May 22, 2019.
Standard models and part numbers
Nine standard models span the two series. SA models are offered with a sapphire window (“M2” suffix) or a calcium fluoride window (“M3”); the SHA models, which Opto Diode designates high power, are supplied in windowless TO-5 packages (“M0”). Peak DC power is the rated input at which the filament reaches 1170 K — exceeding it raises element temperature and decreases source lifetime.
| Model | Factory p/n | Package | Window | Peak DC power |
|---|---|---|---|---|
| SA727-5M2 | 40095 | TO-5 | Sapphire | 1.15 W |
| SA727-5M3 | 40096 | TO-5 | Calcium fluoride | 1.15 W |
| SA1037-5M2 | 40089 | TO-5 | Sapphire | 2.10 W |
| SA1037-5M3 | 40090 | TO-5 | Calcium fluoride | 2.10 W |
| SA727-8M2 | 40198 | TO-8 | Sapphire | 1.2 W |
| SA10510-8M2 | 40092 | TO-8 | Sapphire | 2.7 W |
| SA10510-8M3 | 40093 | TO-8 | Calcium fluoride | 2.7 W |
| SHA727-5M0 | 40100 | TO-5 | Windowless | 1.15 W |
| SHA1037-5M0 | 40099 | TO-5 | Windowless | 2.10 W |
The ordering code reads SA-XXXXX-YYY (or SHA-XXXXX-YYY): the prefix denotes source type — S source, A steady state, with H for high power — XXXXX encodes the filament and foil dimensions, and YYY the packaging and window option.
How steady-state emitters work
The radiating element is a coiled filament whose specialized coating gives a typical emissivity of 0.70 — the ratio of energy radiated by the source to that of a true black-body at the same temperature. Radiated energy scales with the fourth power of absolute temperature, and the peak wavelength follows Wien’s law (λpk × T = 2898, with λ in microns and T in kelvin), so at the rated 1170 K (900 °C) filament temperature the output peaks near 2.5 µm. A built-in reflector shapes the output into near-collimated, uniform radiation — the datasheet describes a parabolic reflector, and the TO-8 package drawing shows an elliptical reflector with a numerical aperture of 0.48.
Drive requirements are simple: any constant-voltage or constant-current DC supply of appropriate rating. Two thermal rules govern lifetime — hold the input at or below the rated peak DC power so the filament stays at 1170 K, and heat-sink the package so it never exceeds 100 °C. Accurate input-power control plus proper heat sinking keep element temperature, and therefore output, constant.
Window options
Standard window materials tailor the output to the wavelength range of interest: 0.5 mm sapphire (M2 models) or 1.0 mm calcium fluoride (M3 models), with transmission curves for both printed in the SA datasheet. The SHA high-power models are windowless (M0), and the SHA datasheet notes the packages come with or without windowing options.
What they are used for
Opto Diode lists these emitters for gas analysis, environmental monitoring, flame detection, medical diagnostics, and scientific instrumentation, with spectroscopy cited across the emitter range. The full emitter range — including the pulsable SVF and PIREPLUS series — is on the IR emitters page, with the steady-state families at SA Series and SHA Series.
Frequently asked questions
What is the difference between SA and SHA Series emitters?
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Both are steady-state (DC) black-body emitters rated for a 1170 K filament temperature. SA Series models come in TO-5 and TO-8 packages with sapphire or calcium fluoride windows; SHA Series models are the high-power variants, supplied in windowless TO-5 packages (SHA727-5M0 and SHA1037-5M0).
What wavelength range do SA and SHA emitters cover?
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They emit a quasi-black-body spectrum with typical emissivity 0.70. At the rated 1170 K filament temperature the output peaks near 2.5 microns per Wien’s law, with broad emission across the infrared; the window choice (sapphire or calcium fluoride) tailors the transmitted range.
How do I drive an SA or SHA emitter?
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Any constant-voltage or constant-current DC power supply of appropriate rating. Operate at or below the rated peak DC power (1.15-2.7 W depending on model) so the filament stays at 1170 K, and heat-sink the package to 100 degrees C or less; exceeding either shortens emitter lifetime.
How do I buy SA or SHA Series emitters?
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Contact Opto Diode directly for pricing, lead time, or a custom configuration; the standard response time for an online request is within 1-2 business days. Opto Diode manufactures the emitters in Camarillo, California, as a division of ITW.
Specifying a steady-state IR source for gas sensing, spectroscopy, or an OEM instrument? Opto Diode typically responds to online requests within 1–2 business days.
Reviewed and updated August 2026.