Optical-fiber based pulsed source of correlated photons is proposed and investigated experimentally. Characteristics and operation of the source is discussed. Single photon generation rate up to 460 000 photons/s at ~925 nm wavelength is demonstrated experimentally.
Quantum key distribution (QKD) enables tap-proof exchange of cryptographic keys guaranteed by the very laws of physics. One of the last remaining roadblocks on the way towards widespread deployment of QKD is the high loss experienced during terrestrial distribution of photons, which limits the distance between the communicating parties. A viable solution to this problem is to avoid the terrestrial distribution of photons via optical fibers altogether and instead transmit them via satellite links, where the loss is dominated by diffraction instead of absorption and scattering. First dedicated satellite missions have demonstrated the feasibility of this approach, albeit with relatively low secure key rates. In order for QKD to become commercially viable, the design of future satellite missions must be focused on achieving higher key rates at lower system costs. Current satellite missions are already operating at almost optimal system parameters, which leaves little room for enhancing the key rates with currently deployed technology. Instead, fundamentally new techniques are required to drastically reduce the costs per secret bit shared between two distant parties. Entanglement-based protocols provide the highest level of security and offer several pathways for increasing the key rate by exploiting the underlying quantum correlations. In this contribution, we review the most relevant advances in entanglement-based QKD which are implementable over free-space links and thus enable distribution of secure keys from orbit. The development of satellite missions is notoriously lengthy. Possible candidates for a new generation of quantum payloads should therefore be scrutinized as early as possible in order to advance the development of quantum technologies for space applications.
Daniel Rieländer, Andrea Di Mira, David Alaluf, Robert Daddato, Sinda Mejri, Jorge Piris, Jorge Alves, Dimitrios Antsos, Abhijit Biswas, Nikos Karafolas, Klaus-Jürgen Schulz, Clemens Heese
The demonstration of interoperability of the deep-space optical ground demonstration infrastructures of the two space agencies, NASA and ESA, will reinforce optical communication for the use case of fast deep-space data return. The operational experience gained by this joint demonstration will enable future mission designers to efficiently trade the option of using optical communication as data-return vehicle for upcoming deep-space missions. ESA is investigating potential mission scenarios at Mars for which this technology demonstration and validation is considered essential. In this paper ESA's ground demonstration infrastructure for optical data return from the Psyche mission is outlined. The deep-space mission to the asteroid Psyche will host a technology demonstration payload, the Deep Space Optical Communication (DSOC) system, developed by NASA. The mission’s objective is to investigate the asteroid and its unique metallic surface. In addition to its primary objective, the mission will demonstrate an optical communication link between the spacecraft and earth with a separation of up to 2.5 AU. Here we provide link budget calculations for the data up- and the data downlink. Optical communication has the potential to deliver 10- to 100 times higher data rate compared to radio frequency, at lower size, weight and power consumption.
In the frame of the Secure And cryptoGrAphic (SAGA) project under ESA ARTES 4.0 program, we report the design and the test of a High-Performance Entangled Photon Source (HP-EPS) dedicated to QKD satellite-based communication, by using the Conventional-band optical fiber telecom components. We developed an asynchronous time binning higher than 10 bits/sec and 5 bits/sec for respectively a 60 dB (LEO) and a 65 dB (GEO) transmission loss budgets (both downlinks combined). The compactness and simplicity of the optical design, the low electrical consumption and the low mass combined with the robustness of the all-fibered design to the space environment (mechanical vibrations, shock, and radiations) make the HP-EPS a valuable and serious candidate for the satellite-based QKD quest.
Scalar magnetometers measure the magnitude of the magnetic field, while vector magnetometers (mostly fluxgate magnetometers) produce three-component outputs proportional to the magnitude and the direction of the magnetic field. While scalar magnetometers have a high accuracy, vector magnetometers suffer from parameter drifts and need to be calibrated during flight. In some cases, full science return can only be achieved by a combination of vector and scalar magnetometers.
KEYWORDS: Semiconductor lasers, High power lasers, Diodes, Astronomical imaging, Space operations, Nitrogen, Oxygen, Contamination, Single crystal X-ray diffraction, Reliability
Several ESA missions incorporate high power laser systems as core constituents of the payload. Instruments based on techniques such as Light Detection And Ranging (LIDAR) can offer extremely accurate measurements of great scientific and industrial interest such as atmosphere composition, wind speed, aerosol presence, topography and water depth, surface backscattering and many more. Other active optical techniques such as Laser Induced Breakdown Spectroscopy (LIBS) enable the remote testing of the composition of rocks. Rendezvous sensors can guide the approach and docking of spacecraft, or assist in the descent of a lander on a surface.
In this work tests for determination of ablation thresholds of various ceramic materials for pulsed laser irradiations at
wavelengths of 355 nm and 1064 nm in vacuum are presented. For comparison tests with copper and aluminium are also
reported. The ablation process was monitored insitu by long-distance microscopy. The morphology of ablation spots was
exsitu inspected by scanning electron microscopy. Furthermore, the redeposition of potentially released particles on
optics in the vicinity to the target was examined.
In this paper we will discuss the challenges of performing comparable laser damage testing as well as a detailed analysis
of the measurements conducted on the samples for this harmonisation activity. The goal of the activity is to enlarge the
test capacities within ESA’s EarthExplorer space program, especially for the missions ADM Aeolus [5] and EarthCare
[6], both having as main payload instruments containing high energy diode pumped nanosecond lasers. Four samples
have been compared with the S-on-1 method according to ISO21254-2, two AR1064/0° windows and two silicon wafers
leading to an agreement of better than 20% concerning the S-on-1 damage threshold.
In the determination of the laser-induced damage threshold (LIDT) of optical coatings former Round-Robin experiments
stand as the empirical foundation for the development of the International Standard as it is known today. In 1983 and
1997 such experiments were conducted at the fundamental wavelength of the Nd:YAG laser under atmospheric
conditions settling the International Standard as it is known today.
To cope with the growing demand of LIDT testing for satellite missions, existing test methods have to be extended to
deal with operation in space-like environments. This requires LIDT measurements performed under customized vacuum
conditions to validate the laser resistance capability and estimate the life time of optical components. To foster the
quality of measurements in such environments the need for an inter-laboratory comparison in vacuum conditions
emerged.
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.