Thin-film slot antennas for 2.5 THz submillimeter radiation were fabri
cated by the photolithographic method on a fused quartz substrate. The
antenna properties were investigated by measuring the antenna pattern
s for 2.5 THz CH3OH laser radiation. It was found that the fabricated
antennas work as receiving antennas at 2.5 THz. The measured antenna p
atterns agreed with the theoretical antenna patterns in free space des
pite the dielectric substrate.