“…This special issue contains twelve research papers covering MEMS mirrors [1,2,3,4,5,6,7,8,9,10], MEMS variable optical attenuators (VOAs) [11], and tunable spectral filters [12]. These MEMS devices are based on three of the commonly used actuation mechanisms: electrothermal [1], electrostatic [2,3,4,5,6,7,11], and electromagnetic actuation [8,9,10]. MEMS optical scanners involving single mirrors are demonstrated or used in [1,2,3,8,9,10], while all other optical microsystems employ MEMS mirror arrays that are all based on DMDs [4,5,6,7].…”