Chip-scale device efficiently boosts light signals

Optical-amplifier devices that boost light signals are workhorses of modern technology, but shrinking them onto microchips requires impractically high power. An amplifier architecture has been developed that recycles its own ‘pump’ energy to achieve high performance at power levels ten times lower than those of previous designs, making low-power, chip-scale optical amplification practical. The optical amplifier uses levels of power similar to those available to microchip laser systems.