According to LEDinside’s 2018 Infrared Sensing Application Market Report, pulse oximeter heart rate sensors have been widely introduced into smartwatch and wristband markets, pushing the demand for infrared optical components. Apple is expected to increase the accuracy of pulse oximeter heart rate sensors in its new-generation Apple Watch, thus may double the amount of green LEDs and infrared LEDs used in the products. The amount of photodiode needed for the new products may be four to five times more than in previous models, and the photodiode will also be larger in size.