Optical systems based on fluid-fluid interface are gaining great attention because they offer added advantages such as dynamic, reconfigurable, and self-healing capabilities with less complex fabrication steps compared to the solid based optical elements. Moreover, cost-effectiveness and ease of miniaturization pave a potential route towards the realization of portable optical and optofluidic devices. However, a single optofluidic device having remotely controlled multifunctional capabilities remains a challenge. We demonstrate an optofluidic multifunctional strategy, which could operate either as an optical switch or a tunable liquid lens. The principle relies on light-controlled volumetric change of an air plug confined in a minichannel filled with water. For the optical switch, volumetric change of the air plug modulates total internal reflection. A temperature difference of only 0.2 °C is sufficient for a subsecond switching time (0.6 ± 0.1 s). For the liquid lens, the change of plug size acts as an actuator to control the meniscus shape of the liquid. Upon heating or cooling, the meniscus develops a convex or a concave lens respectively. A temperature difference of 0.1–0.7 °C is sufficient for realizing tunability in the focal length. The demonstrated strategy is simple, cost-effective, non-contact and the device could be operated at room temperature.