Imaging systems and method of optical imaging. One example of an imaging system includes an optical scanning subsystem including an optical source and a MEMS MMA, the MEMS MMA being configured to direct optical radiation generated by the optical source over an area of a scene, a detection subsystem including an optical sensor configured to collect reflected optical radiation from the area of the scene, and a fused fiber focusing assembly including a fused fiber bundle, a plurality of lenses coupled together and positioned to receive and focus the reflected optical radiation from the area of the scene directly onto the fused fiber bundle, a microlens array interposed between the fused fiber bundle and the optical sensor and positioned to receive the reflected optical radiation from the fused fiber bundle, and a focusing lens positioned to direct the reflected optical radiation from the microlens array onto the optical sensor. The MEMS MMA may be further configured to generate and independently steer multiple beams of optical radiation, at the same or different wavelengths, to more fully interrogate the area of the scene. The MEMS MMA through its Piston capability may be further configured to shape the optical beam(s) to execute a variety of optical functions within the beam steering device.