HIGH-WAVELENGTH-RESOLUTION EXTREME-ULTRAVIOLET MULTILAYER MIRROR

Multilayer mirrors with a system wavelength resolution (lambda/Delta l ambda) as high as 3050 are required for the diagnostics of cosmic plas mas with temperatures of 1-20 MK. Such a high wavelength resolution ca n be realized by increasing the number of layer pairs contributing to the reflectance, by selecting less-absorbing materials for both the re flector and the spacer, and by decreasing the thickness of the reflect or. We have fabricated a multilayer mirror tuned to 284 Angstrom with a silicon carbide reflector (20% thickness of the layer period) and an aluminum spacer and achieved lambda/Delta lambda similar to 26.8 with a peak reflectivity of similar to 13.0%. This wavelength resolution i s close to the value obtained with a numerical simulation and is consi derably higher than the value obtained with the conventional Mo/Si mul tilayer. (C) 1997 Optical Society of America.