High-speed (upwards of 105 coordinates s-1) and long-range (~10 m) absolute distance measurement applications based on frequency scanning interferometry (FSI) generate very high modulation frequencies (typically >100 GHz) due to the laser frequency sweep rate and the large imbalance between the reference and object arms. Such systems are currently impractical due to the extremely high cost associated with sampling at these signal frequencies. Adaptive delay lines (ADLs) were recently proposed as a solution to balance the interferometer and therefore reduce sampling rate requirements by a factor of 2N, where N is the number of switches in the ADL [1, 2]. The technique has been successfully demonstrated in the lab using bulk optics and optical fiber configurations, and further reduction in size and cost will increase the breadth of metrology applications that can be addressed. Silicon photonics constitute an effective platform to miniaturize ADLs to chip-scale, simplifying instrument manufacture and providing a more robust configuration compared to bulk-optics and fiber-based solutions. We discuss the design and fabrication of chip-scale ADLs on a silicon on insulator (SOI) photonics platform, using optical switches based on heaters, multi-mode interferometer (MMI) couplers and Mach-Zehnder interferometers (MZI). We also establish the heater voltages of 4 switches in series, required to switch the optical path in the reference arm, a necessary step to use the device for FSI range measurements.
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.