Optical spectroscopy is among the most important chemical analysis techniques, due to its high specificity and long-term stability. For spectroscopic analysis of gas compositions, the mid infrared (mid-IR) region is particularly important, owing to the rovibrational resonances in that spectral range. Hence, there is great interest in miniaturizing and reducing the power consumption of optical spectroscopic sensors, but until recently the mid-IR range has been out of reach. We demonstrate spectroscopic sensing of carbon dioxide using an integrated silicon waveguide at the strong absorption peak at 4.23 µm wavelength. We show different measurement principles that leverage the power of integrated optics in innovative ways.
We present a method to characterize the temperature dynamics of miniaturized thermal IR sources. The method circumvents the limitations of current IR photodetectors, by relying only on an electrical measurement rather than on optical detection. Thus, it enables the characterization of the light emission of IR sources over their full operation frequency range. Moreover, we develop a model of thermal IR sources allowing simulations of their thermal and electrical behavior. By combining measurements and modeling, we achieve a comprehensive characterization of a Pt nanowire IR source: the reference resistance R0 = 17.7Ω, the TCR α = 2.0 × 10-3 K-1, the thermal mass C = 2.7 × 10-14 J/K, and the thermal conductance G = 1.3 × 10-6 W/K. The thermal time constant could not be measured, because of the frequency limitation of our setup. However, the operation of the source has been tested and proved to function up to 1 MHz, indicating that the thermal time constant of the source is smaller than 1 μs.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.