Lock-in imaging of multicycle integration focal plane array

Lock-in imaging using multicycle integration focal plane array (MIFPA) is demonstrated to detect extremely weak image and/or spectroscopic signals. Each pixel of the MIFPA has a correlated multicycle integrator to play the roles of lock-in's phase-sensitive detector and low-pass filter. In lock-in imaging, the signal current is accumulated while the dark or background current is canceled. As a result, the total integration time is increased by several orders, which is equivalent to the reduction of bandwidth by several orders. All advantages associated with the lock-in amplifier are achieved by imaging with MIFPA. Key issues of the MIFPA technology, including the design and performance of the correlated multicycle integrator, are discussed. (C) 2002 American Institute of Physics.