NASA Goddard Space Flight Center is developing a master oscillator power amplifier (MOPA) laser transmitter for the ESA-led Laser Interferometer Space Antenna (LISA) mission. Taking advantage of our space laser experience and the emerging telecom laser technology, we are developing a full laser system for the LISA mission. Our research effort has included both master oscillator (MO) and power amplifier (PA) developments, and their environmental testing and reliability for space flight. Our current baseline for the MO is a low-mass, compact micro non-planar ring oscillator (m- NPRO) laser. The amplifier uses a robust mechanical design based on fiber components. We have performed laser system noise tests by amplitude- and frequency-stabilizing the PA output. We will describe our progress and plans to demonstrate a TRL 6 laser system, which is an essential step toward qualifying lasers for space applications, by 2021.
A highly stable and long-lifetime laser system is a key component of the space-based Laser Interferometer Space Antenna (LISA) mission, which is designed to detect gravitational waves from various astronomical sources. We are developing such laser system at the NASA Goddard Space Flight Center (GSFC). Our baseline architecture for the LISA laser consists of a low-power, low-noise small Nd:YAG non-planar ring oscillator (micro NPRO) followed by a diodepumped Yb-fiber amplifier with ~2 W output. In this paper, we will describe our progress to date and plans to demonstrate a technology readiness level (TRL) 6 LISA laser system.
We studied and demonstrated a wavelength discriminant structure that consists of one circulator, one or more Fiber Bragg Gratings and two photodiodes. The discriminants are built in NASA’s LCRD (Laser Communication Relay Demonstration) flight modems to measure the transmitter and pilot laser wavelengths on orbit. The performance of the discriminants is evaluated in ambient and thermal vacuum chamber environment. The paper reports on results of a few discriminants working at different wavelengths and power levels. The trending of the discriminant performance under ambient and TVAC cycles is discussed. The discriminant can achieve sub-picometer wavelength accuracies if calibrated properly.