Injection mode infrared detector concepts are expanded to incorporate the nonlinear dynamics concept of mode locking. The first successful demonstration of this approach is reported. The detectors employ extrinsic silicon and have large output signals which require no electronic amplification. Mode locking greatly reduces fluctuations in detector output without a corresponding reduction in detector responsivity. The results could lead to the development of a new class of sensors which exploit recent work on the distinction between deterministic fluctuations in nonlinear systems and intrinsic noise.