Variable, two-color acquisition beam for free-space laser communication terminals

Jeffrey M. Roth; Shankararaman Ramakrishnan; Robert J. Murphy; Alicia M. Volpicell; Stephen Rauch; Michael S. Andrle; Alexander J. King; Brett Reynolds; John A. Taylor; Ronald R. Parenti; John Chang; Todd G. Ulmer

doi:10.1117/12.2513964

4 March 2019 Variable, two-color acquisition beam for free-space laser communication terminals

Jeffrey M. Roth, Shankararaman Ramakrishnan, Robert J. Murphy, Alicia M. Volpicell, Stephen Rauch, Michael S. Andrle, Alexander J. King, Brett Reynolds, John A. Taylor, Ronald R. Parenti, John Chang, Todd G. Ulmer

Author Affiliations +

Proceedings Volume 10910, Free-Space Laser Communications XXXI; 109100Q (2019) https://doi.org/10.1117/12.2513964
Event: SPIE LASE, 2019, San Francisco, California, United States

Abstract

This paper reports on a two-color acquisition beam with continuously variable divergence for free-space laser communication links. This approach is useful for terminals using wavelength-separated beacon and communi- cation signals amplified by a common high-power optical amplifier (HPOA). The acquisition beam features a controllable power-split ratio between the two waveforms that varies during the acquisition sequence. With this scheme, the area of the acquisition beam can be expanded by a factor of 100, while maintaining power levels of the two colors within a specified range on an acquisition sensor in a partner terminal. An optical transmitter produces beacon and communication waveforms from distinct master oscillators, and balances these signal levels during a multi-step transition sequence to achieve the desired relative power levels at each wavelength. An HPOA then boosts this transmitter signal to power levels necessary to overcome link losses. The HPOA and transmitter adjust power levels during the sequence to maintain beacon and communication irradiances within specified ranges. A divergence setting assembly (DSA) simultaneously adjusts the beam width from a 10x broadened beacon to a narrow, diffraction-limited beam. We demonstrate control of the on-axis beacon power to within a 10-dB dynamic range while the beacon area varies by a factor of approximately 20 dB. This paper describes the hardware and software control of the various units used to perform acquisition.

Conference Presentation

Citation Download Citation

Jeffrey M. Roth, Shankararaman Ramakrishnan, Robert J. Murphy, Alicia M. Volpicell, Stephen Rauch, Michael S. Andrle, Alexander J. King, Brett Reynolds, John A. Taylor, Ronald R. Parenti, John Chang, and Todd G. Ulmer "Variable, two-color acquisition beam for free-space laser communication terminals", Proc. SPIE 10910, Free-Space Laser Communications XXXI, 109100Q (4 March 2019); https://doi.org/10.1117/12.2513964

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

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.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available