Compact Optical Interrogator

Free Space Optical Communications
Compact Interrogator 

NovaSol has developed a compact version of its successful Dual Mode Optical Interrogator (DMOI) for free space optical communications (FSOC).

Taking advantage of technology advances in signal detection and pointing, acquisition, and tracking, the compact interrogator (CI) achieves better performance in a substantially smaller system. 


The self-contained CI is 12” x 10” x 11”. It weighs less than 30 lbs, and has a peak power draw of 75-100W, depending on application. The CI includes all photonics, electronics, and onboard processing. The only external connections are a power cable, ethernet cable, and optional gimbal control cable. 

The CI is designed for portable on-the-move applications, particularly to support communications with miniature modulating retroreflector (MRR) terminals. It can be transported and operated by a single person. It also comes with a 25 lb gimbal for automatic, unattended use. The gimbal permits stabilized operation from moving platforms. It supports automatic scanning and acquisition of poorly-located MRRs, and can support polling protocols for data exfiltration from multiple MRRs.

The CI provides a full duplex data link. MRR comms have been supported up to 10 Mbps downlink (MRR to interrogator) and 2 Mbps uplink (interrogator to MRR). Retransmission-on-demand protocols give full TCP/IP functionality, although a UDP-like mode is also available for real-time voice/video transmission.

The dual-mode CI also supports direct interrogator-to-interrogator links using a pair of CIs. This gives multi-Gbps communications at ranges of tens of miles.

The CI currently operates at a solid TRL 5. It has undergone environmental testing by the Navy, and has been eye-safety certified by the Navy’s Laser Safety Review Board. 

             Compact Interrogator Performance Specifications

Pointing, Acquisition & Tracking: 
  • Can acquire and track moving remotes 
  • A&T FOV 2 degrees (internal)
  • Gimbal-adapted for moving platforms, autonomous operation
  • Tracking sensor sensitivity better than -70dBm at 5kHz
  • Receive beam corrected for angle-of-arrival fluctuations
  • Transmit beam corrected for beam wander

Optics:
  • Bistatic design with independently steered beams for mechanical  
     robustness and ease of alignment
  • Wavelength: 1.55um
  • Output power: to 2W
  • Integrated spotting scope

Interface:
  • Power: 28V
  • Data: Ethernet 10/100/1000T
  • Gimbal: power/control

Electrical:
  • Max power: 75-100W, depending on transmit beam power and tracking
     regime

Mechanical:
  • Size: 12" x 10" x 11”
  • Weight: 30 lbs
  • Gimbal: 25 lbs