<title>Performance test result of LUCE (laser utilizing communications equipment) engineering model</title>

Abstract

NASDA (National Space Development Agency of Japan) have developed OICETS (Optical Inter-Orbit Communications Engineering Test Satellite) since 1993 in order to get the acquisition, tracking and pointing technology for optical inter-satellite communications through the in-orbit experiment with ARTEMIS (Advanced Relay and TEchnology Mission Satellite) of ESA (European Space Agency). The engineering model (EM) of the optical terminal called LUCE (Laser Utilizing Communications Equipment) was tested and its optical performance was evaluated during the thermal vacuum test. The on-axis intensity transmitted from the terminal was about 560 MW/Sr with 90 mW of the averaged semiconductor laser output. The full width of the far field pattern of the emitted beam at the point of 1/e 2 was about 9.4 μradian. The acquisition, tracking and pointing performance and the quality of communication link was tested in the ambient condition and the vacuum condition. The response time between the incidence of the beam into LUCE and the transmission to the direction of ARTEMIS was less than 350 mseconds. Less than 1 μradian of the tracking error was obtained under the condition that the irradiance on the LUCE was more than 5 nW/m 2 during the communication phase. The link quality of BER 10 -6 of the forward link from ARTEMIS was realized at the irradiance more than 9 nW/m 2 on LUCE. In this paper the details of the LUCE EM test conditions and result are reported.