Newsroom
Optical Frequency
Transfer Solutions
RLS for bidirectionnal point to point frequency transfer, MLS for bidirectionnal star structure of your frequency transfer network
Turn-key industry-grade solution for optical frequency transfer over optical fibers
Exail proposes all the hardware and software to enable long-haul optical frequency dissemination over optical fibers. Regeneration Laser Stations and bi-directional optical amplifiers are cascaded along an optical fiber to cover distances as long as thousands of kilometers while preserving the frequency stability provided by the best optical clocks in the world. Our technology was designed to transfer the metrological optical reference signal on a dark channel of the DWDM spectrum in parallel of Internet data traffic, but it can also work on a dark fiber. Exail offers the world’s only industry-grade solution at this level of performance.
Regeneration Laser Station (RLS)
The Regeneration Laser Station (RLS) is a stand-alone system that actively compensates the phase noise introduced by the fiber links and provides an ultra-stable output laser in the ITU channel 44 (1542.14 nm, other wavelengths available on demand).
It enables also to cascade fiber links in order to set-up long-distance frequency dissemination. It has been designed to be installed in a Telecom network nodes in respect to NF/EN 60950-1 and NF/EN 60825-1 norms. It can work both on a dark channel and on a dark fiber.
Datasheet
Multi-Branch Laser Station (MLS)
The MLS is a stand-alone system that actively compensates the phase noise introduced by the fiber links and provides an ultra-stable output frequency equivalent to the input reference. The station compensates the fiber noise of up to 6 parallel branches and collects the incoming down-link signal to assess the round-trip residual instability.
The MLS therefore includes a multi-channel ultra-low noise optical interferometer, the electronics for noise compensation of up to 6 links, and the electronics for round-trip heterodyne detection. The station is fully compatible with Exail RLS and allows to extend the capabilities of a metrological fiber network to star topologies.
Datasheet
Features
- Fully secured communication for supervision protocol: SSH, SNMP
- Supervision tool deployable through usual internet connection
- User-friendly webapp interfaces
- Remote access and real-time data retrieval
The supervision tool
Exail’s solutions for optical frequency transfer can be deployed within a few days and has shown to provide uptimes as high as 99 % over a week. This is enabled by the remote and automated operation of the hardware supervised by a global supervision tool.
The supervision tool
The supervision tool is composed of:
- A supervision software
To monitor and control the REFIMEVE+ performances - A database
Store all the information useful to the network management - A human-machine interface
For end users, academic teams and the telecom network manager
The supervision tool of the REFIMEVE+ network currently monitors more than 150 pieces of equipment (EDFA, RLS, frequency counters). It enables the secured full remote access to all the equipment (RLS, ES, UM, EDFA) via the hosting telecom network infrastructure.
The supervision software
The supervision software is in charge of
- Monitoring the proper functioning and remotely control the equipment parameters in real-time.
- Detecting and managing bugs and alarms (cycle slips, polarization optimizations, …)
- Uploading the information collected on the field and store in the database (alarm, events, …)
- Administrating and troubleshooting system configurations
- Pre-processing data: outliers detection, Allan Deviation calculation, …
Fig. 1: Fractional frequency instability calculated from data recorded with Λ-counter and 1 s gate time versus averaging time. Dark red squares, modified Allan deviation for a compensated 200 km laboratory link; light red circles, modified Allan deviation for the free-running 200 km laboratory link; dark green stars, modified Allan deviation for a short link to estimate the noise floor of the RLS; light green diamonds, modified Allan deviation for the free-running short link.
Fig 2: End-to-end phase fluctuations after propagation over a 680 km fiber link. Data from F. Guillou-Camago et al., « First industrial-grade coherent fiber link for optical frequency standard dissemination», Applied Optics, Vol. 57, No. 25 (2018)
Specifications
 | RLS | MLS |
|---|---|---|
Central wavelength | 1542 nm (ITU Channel 44) (other wavelengths in option) | 1542 nm (ITU Channel 44) (other wavelengths in option) |
NOISE FLOOR | ||
Relative short term frequency stability | < 3×10-17 @1 s | < 3×10-17 @1 s |
Relative long term frequency stability (noise floor) | < 2×10-20 @103 s | < 2×10-21 @103 s |
Typical accuracy of fiber link | < 1e-19, depending on link characteristics | < 1e-19, depending on link characteristics |
Temperature sensitivity of the interferometer | < 1 fs / °C | < 1 fs / °C |
MASS AND DIMENSIONS | ||
Number of boxes | 2 | 6 to 8 |
Mass | 16.7 kg for the RLS 4 kg for power supply | 55 kg max |
Dimensions | 5U 19’’ rack for the RLS (485 mm x 222 mm x 540 mm) 2U 19’’ rack for the power supply unit (485 mm x 90 mm x 250 mm) | 19’’ rack, 545 mm depth for the MLS, from 11 to 13U depending on the configuration |
ELECTRICAL RATINGS | ||
Supply voltage | 100-240 Vac | 100-240 Vac |
Frequency | 50-60 Hz | 50-60 Hz |
Power | <110 W | 150 W |
Current | 2A | 2A |
OPTICAL RATINGS | ||
Class | 3R | 3R |
Output power | <3 dBm | <2mW per branch |
Input power | -60 dBm < P < 3 dBm | -60 dBm < P < 3 dBm |
Wavelength | 1542 nm + custom | 1542 nm + custom |
Regime | CW | CW |
SYSTEM INTERFACE & CONTROL | ||
Optical connectors | FC/APC | LC/APC |
Communication connectors | RJ45 | RJ45 |
Communication protocol | SSH, SNMP | SSH, SNMP |
Degree of Ingress Protection | IP 30 | IP 30 |
ENVIRONMENTAL & PHYSICAL SPECIFICATIONS | ||
Operating temperature | [15 ; 35] °C | [15 ; 35] °C |
Storage temperature | [5 ; 30] °C | [5 ; 30] °C |
Humidity | Maximum relative humidity 80 % for temperatures up to 31 °C decreasing linearly to 50 % relative humidity at 40 °C | Maximum relative humidity 80 % for temperatures up to 31 °C decreasing linearly to 50 % relative humidity at 40 °C |
