The number of satellites is rapidly growing, hence the demand for increasingly precise knowledge of the satellites’ orbital parameters is essential to avoid collisions, debris, and efficient use of the orbits. Recognizing, cataloging, and measuring with better confidence are actions crucial to preserve the health of crewed and uncrewed flying objects. Moreover, strategies to distinguish them may vary: TNO is developing suitable optical instrumentation for flying object reconnaissance along these two main paths. The satellite license plate (SLP) is a collaborative method based on a tag mounted on the satellite before launch. This plate consists of retroreflectors and wisely arranged bandpass filters. Therefore, it is passive and needs no power as opposed to an onboard radio beacon. Once a ground-based laser terminal illuminates the tag attached to the satellite, it sends back to Earth a signal encoding a unique identifier in the spectral domain. The current activities of TNO focus on proof-of-principle experiments in relevant environments (free-space tests over 2.5 km distances) and system design.
Long optical storage times are an essential requirement to establish high-rate entanglement distribution over large distances using memory-based quantum repeaters. Rare earth ion-doped crystals are arguably well-suited candidates for building such quantum memories. Toward this end, we investigate the 795.32 nm 3H6 ↔ 3H4 transition of 1% thulium-doped yttrium gallium garnet crystal (Tm3+:Y3Ga5O12 : Tm3+:YGG). Most essentially, we find that the optical coherence time can reach 1.1 ms, and, using laser pulses, we demonstrate optical storage based on the atomic frequency comb (AFC) protocol up to 100 µs. In addition, we demonstrate multiplexed storage, including feed-forward selection, shifting, and filtering of spectral modes, as well as quantum state storage using members of non-classical photon pairs. Our results show that Tm:YGG can be a potential candidate for creating multiplexed quantum memories with long optical storage times.
We present a time-polarization multiplexing setup that overcomes the maximum amplification limit of semiconductor optical amplifiers (SOAs) in the pulsed regime. A coherent optical pulse at the input is equally divided into two, which are independently amplified, and coherently recombined to compose an oversaturation amplified optical pulse at the output. This simple topology, containing an SOA and few extra devices, offers 1.96-dB oversaturation gain in comparison with a single SOA. Furthermore, little experimental complexity and, thus, cost, are required by the proposed topology.
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.