摘要:
The present invention includes: a light-transmissive reaction cell (21) into which a process gas is supplied and the process gas is photochemically reacted by laser light; a metal mirror (19) which is set up outside of the light-transmissive reaction cell (21) so as to encompass the light-transmissive reaction cell (21), and which reflects laser light; and a cryostat (11) which is configured to accommodate the light-transmissive reaction cell (21), the metal mirror (19), and a cryogenic liquid (12), and which maintains a temperature of the metal mirror (19) at a cryogenic temperature by the cryogenic liquid (12).