An optical detection device for biochemically analyzing samples of microfluidic chips such as DNA chips or protein chips is provided. The optical detection device includes a light source for generating excitation light to excite a sample, a detection plate having an optical waveguide with the sample mounted thereon, a linear symmetry lens for shaping the excitation light into a desired shape having a uniform intensity distribution and transmitting it to the detection plate, and a detector for detecting radiation from the sample.