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Silicon photonic crystal thermal emitter at near-infrared wavelengths.

O'Regan BJ, Wang Y, Krauss TF - Sci Rep (2015)

Bottom Line: The device is resistively heated by passing current through the photonic crystal membrane.At a temperature of ≈1100 K, we observe relatively sharp emission peaks with a Q factor around 18.A support structure system is implemented in order to achieve a large area suspended photonic crystal thermal emitter and electrical injection.

View Article: PubMed Central - PubMed

Affiliation: School of Physics &Astronomy, University of St Andrews, St Andrews, KY16 9SS, UK.

ABSTRACT
Controlling thermal emission with resonant photonic nanostructures has recently attracted much attention. Most of the work has concentrated on the mid-infrared wavelength range and/or was based on metallic nanostructures. Here, we demonstrate the experimental operation of a resonant thermal emitter operating in the near-infrared (≈1.5 μm) wavelength range. The emitter is based on a doped silicon photonic crystal consisting of a two dimensional square array of holes and using silicon-on-insulator technology with a device-layer thickness of 220 nm. The device is resistively heated by passing current through the photonic crystal membrane. At a temperature of ≈1100 K, we observe relatively sharp emission peaks with a Q factor around 18. A support structure system is implemented in order to achieve a large area suspended photonic crystal thermal emitter and electrical injection. The device demonstrates that weak absorption together with photonic resonances can be used as a wavelength-selection mechanism for thermal emitters, both for the enhancement and the suppression of emission.

No MeSH data available.


Related in: MedlinePlus

Calibration of the PhC slab temperature by tracking a resonance.(a) Measured reflection spectrum for the resistively heated PhC, at room temperature (0 V) and for seven different applied voltages: 30 V, 50 V, 56 V, 60 V, 66 V, 70 V and 76 V. Two Lorentzians are fitted to the reflection resonances (shown here for the case of room temperature and the highest obtained temperature with a voltage of 76 V) in order to track the peak wavelength of the resonances accurately. (b) The black solid line represents the thermal coefficient (0.07 nm/K) for the PhC which was calculated using an external heater that reached a maximum surface temperature of 740 K. The linear extrapolation of this coefficient to higher temperatures is also shown. The solid magenta dots represent the peak position of the left hand (short wavelength) reflection resonance (indicated with the magenta Lorentzian fit in panel (a)) as the voltage increases, with the seven reflection resonances from panel (a) highlighted. Using the calculated (and extrapolated) thermal coefficient value, the applied voltage can be accurately mapped onto the corresponding temperature value.
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f7: Calibration of the PhC slab temperature by tracking a resonance.(a) Measured reflection spectrum for the resistively heated PhC, at room temperature (0 V) and for seven different applied voltages: 30 V, 50 V, 56 V, 60 V, 66 V, 70 V and 76 V. Two Lorentzians are fitted to the reflection resonances (shown here for the case of room temperature and the highest obtained temperature with a voltage of 76 V) in order to track the peak wavelength of the resonances accurately. (b) The black solid line represents the thermal coefficient (0.07 nm/K) for the PhC which was calculated using an external heater that reached a maximum surface temperature of 740 K. The linear extrapolation of this coefficient to higher temperatures is also shown. The solid magenta dots represent the peak position of the left hand (short wavelength) reflection resonance (indicated with the magenta Lorentzian fit in panel (a)) as the voltage increases, with the seven reflection resonances from panel (a) highlighted. Using the calculated (and extrapolated) thermal coefficient value, the applied voltage can be accurately mapped onto the corresponding temperature value.

Mentions: Figure 7(a) shows the measured reflection spectrum for the PhC resistively heated for seven different applied voltages: 30 V, 50 V, 56 V, 60 V, 66 V, 70 V and 76 V. Each reflection curve is a superposition of multiple Lorentzian resonances. Accordingly, we fitted two Lorentzian curves to accurately track the position of each resonant wavelength (shown for the room temperature (0 V) and the high bias 76 V spectra in Fig. 7(a)) for each applied voltage. For the high voltage case of 76 V, the two Lorentzians almost completely overlap and hence have very similar resonant wavelengths. The same fitting and resonance tracking procedure was applied to the reflection data measured with the device on the external heater. This method allows us to determine the relationship between the temperature of the PhC and the resonant reflection wavelength. The black solid line in Fig. 7(b) shows this relationship with a measured thermal coefficient of 0.07 nm/K for the short wavelength resonance, which corresponds to the thermal coefficient of silicon (0.12 nm/K) multiplied by the overlap (Γ ≈ 60%) with the silicon material for this particular mode. Since we were unable to achieve surface temperatures higher than 740 K with the available heater, we extrapolated the line to higher temperatures as a very good linear fit to the data was achieved. Figure 7(b) shows how the temperature for each reflection measurement is determined by using the peak of the reflection resonance for the short wavelength Lorentzian fit mapped onto the thermal coefficient line, with each of the reflection resonances shown in panel (a) individually marked in (b). We estimate an error of +/− 10% for this temperature calibration method.


Silicon photonic crystal thermal emitter at near-infrared wavelengths.

O'Regan BJ, Wang Y, Krauss TF - Sci Rep (2015)

Calibration of the PhC slab temperature by tracking a resonance.(a) Measured reflection spectrum for the resistively heated PhC, at room temperature (0 V) and for seven different applied voltages: 30 V, 50 V, 56 V, 60 V, 66 V, 70 V and 76 V. Two Lorentzians are fitted to the reflection resonances (shown here for the case of room temperature and the highest obtained temperature with a voltage of 76 V) in order to track the peak wavelength of the resonances accurately. (b) The black solid line represents the thermal coefficient (0.07 nm/K) for the PhC which was calculated using an external heater that reached a maximum surface temperature of 740 K. The linear extrapolation of this coefficient to higher temperatures is also shown. The solid magenta dots represent the peak position of the left hand (short wavelength) reflection resonance (indicated with the magenta Lorentzian fit in panel (a)) as the voltage increases, with the seven reflection resonances from panel (a) highlighted. Using the calculated (and extrapolated) thermal coefficient value, the applied voltage can be accurately mapped onto the corresponding temperature value.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4544018&req=5

f7: Calibration of the PhC slab temperature by tracking a resonance.(a) Measured reflection spectrum for the resistively heated PhC, at room temperature (0 V) and for seven different applied voltages: 30 V, 50 V, 56 V, 60 V, 66 V, 70 V and 76 V. Two Lorentzians are fitted to the reflection resonances (shown here for the case of room temperature and the highest obtained temperature with a voltage of 76 V) in order to track the peak wavelength of the resonances accurately. (b) The black solid line represents the thermal coefficient (0.07 nm/K) for the PhC which was calculated using an external heater that reached a maximum surface temperature of 740 K. The linear extrapolation of this coefficient to higher temperatures is also shown. The solid magenta dots represent the peak position of the left hand (short wavelength) reflection resonance (indicated with the magenta Lorentzian fit in panel (a)) as the voltage increases, with the seven reflection resonances from panel (a) highlighted. Using the calculated (and extrapolated) thermal coefficient value, the applied voltage can be accurately mapped onto the corresponding temperature value.
Mentions: Figure 7(a) shows the measured reflection spectrum for the PhC resistively heated for seven different applied voltages: 30 V, 50 V, 56 V, 60 V, 66 V, 70 V and 76 V. Each reflection curve is a superposition of multiple Lorentzian resonances. Accordingly, we fitted two Lorentzian curves to accurately track the position of each resonant wavelength (shown for the room temperature (0 V) and the high bias 76 V spectra in Fig. 7(a)) for each applied voltage. For the high voltage case of 76 V, the two Lorentzians almost completely overlap and hence have very similar resonant wavelengths. The same fitting and resonance tracking procedure was applied to the reflection data measured with the device on the external heater. This method allows us to determine the relationship between the temperature of the PhC and the resonant reflection wavelength. The black solid line in Fig. 7(b) shows this relationship with a measured thermal coefficient of 0.07 nm/K for the short wavelength resonance, which corresponds to the thermal coefficient of silicon (0.12 nm/K) multiplied by the overlap (Γ ≈ 60%) with the silicon material for this particular mode. Since we were unable to achieve surface temperatures higher than 740 K with the available heater, we extrapolated the line to higher temperatures as a very good linear fit to the data was achieved. Figure 7(b) shows how the temperature for each reflection measurement is determined by using the peak of the reflection resonance for the short wavelength Lorentzian fit mapped onto the thermal coefficient line, with each of the reflection resonances shown in panel (a) individually marked in (b). We estimate an error of +/− 10% for this temperature calibration method.

Bottom Line: The device is resistively heated by passing current through the photonic crystal membrane.At a temperature of ≈1100 K, we observe relatively sharp emission peaks with a Q factor around 18.A support structure system is implemented in order to achieve a large area suspended photonic crystal thermal emitter and electrical injection.

View Article: PubMed Central - PubMed

Affiliation: School of Physics &Astronomy, University of St Andrews, St Andrews, KY16 9SS, UK.

ABSTRACT
Controlling thermal emission with resonant photonic nanostructures has recently attracted much attention. Most of the work has concentrated on the mid-infrared wavelength range and/or was based on metallic nanostructures. Here, we demonstrate the experimental operation of a resonant thermal emitter operating in the near-infrared (≈1.5 μm) wavelength range. The emitter is based on a doped silicon photonic crystal consisting of a two dimensional square array of holes and using silicon-on-insulator technology with a device-layer thickness of 220 nm. The device is resistively heated by passing current through the photonic crystal membrane. At a temperature of ≈1100 K, we observe relatively sharp emission peaks with a Q factor around 18. A support structure system is implemented in order to achieve a large area suspended photonic crystal thermal emitter and electrical injection. The device demonstrates that weak absorption together with photonic resonances can be used as a wavelength-selection mechanism for thermal emitters, both for the enhancement and the suppression of emission.

No MeSH data available.


Related in: MedlinePlus