Next Article in Journal
Parameters Sensitivity Analysis of Position-Based Impedance Control for Bionic Legged Robots’ HDU
Next Article in Special Issue
Effect of Molybdenum on the Microstructures and Properties of Stainless Steel Coatings by Laser Cladding
Previous Article in Journal
Modeling Coloration of a Radiochromic Film with Molecular Dynamics-Coupled Finite Element Method
Previous Article in Special Issue
A High-Energy, 100 Hz, Picosecond Laser for OPCPA Pumping
Article Menu
Issue 10 (October) cover image

Export Article

Open AccessArticle
Appl. Sci. 2017, 7(10), 1032;

Fast Frequency Acquisition and Phase Locking of Nonplanar Ring Oscillators

School of Optoelectronic Information, University of Electronic Science and Technology of China, Chengdu 610054, China
Author to whom correspondence should be addressed.
Academic Editor: Federico Pirzio
Received: 26 August 2017 / Revised: 30 September 2017 / Accepted: 4 October 2017 / Published: 9 October 2017
(This article belongs to the Special Issue Solid State Lasers Materials, Technologies and Applications)
Full-Text   |   PDF [1641 KB, uploaded 10 October 2017]   |  


Optical phase locking is a critical technique in space coherent optical communication and active coherent laser beam combining. In a typical optical phase locking loop based on nonplanar ring oscillators, the pull-in range is normally less than 1 MHz, limited by loop delay and frequency tuning bandwidth of the laser source. Phase locking cannot be achieved at large initial frequency differences. In this work, a fast laser frequency acquisition method is demonstrated. The frequency difference between the signal and local lasers was measured via frequency dividing and period counting, and the frequency control signal was generated by a frequency discrimination and control module, to reduce the frequency difference to the pull-in range of the loop. Under the coordinating function of the loop filter and the frequency discrimination and control module, phase locking under a large initial frequency difference was achieved. The frequency acquisition range reached 164 MHz, and the acquisition and locking time was measured to be 440 ms. Additionally, the acquisition time was shortened with the decrease in initial frequency difference. View Full-Text
Keywords: optical phase-locking loop; frequency acquisition; coherent optical communication; frequency discrimination optical phase-locking loop; frequency acquisition; coherent optical communication; frequency discrimination

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Share & Cite This Article

MDPI and ACS Style

Wang, Y.; Wang, C.; Tao, Y.; Liu, Y.; Zhou, Q.; Su, J.; Wang, Z.; Shi, S.; Qiu, Q. Fast Frequency Acquisition and Phase Locking of Nonplanar Ring Oscillators. Appl. Sci. 2017, 7, 1032.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Appl. Sci. EISSN 2076-3417 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top