We fabricate a series of mesa type InGaAs infrared detectors with different areas.We use perimeter-to-area analysis to investigate the dark current mechanism and low frequency noise characteristic of these detectors.In these detectors the generation-recombination(g-r) currents that are related to mesa edge and the bulk dominate the total dark current.The results of the noise measurement show that,at low frequencies the detectors are 1/f noise dominated.The total noise becomes larger with the increasing edge...