Novel LED's driver circuit for broadband short-range optical fiber communication systems

Compared to laser diode, LED offers advantages such as lower cost, better temperature stability and longer service life. LED is therefore the preferred choice for optical communication systems when environmental conditions are uncontrolled. However, modulation rate of LED and RC-LED at 100 Mb/s and 200 Mb/s, respectively, is much lower than that of tens of Gb/s in LD and VCSEL. Our newly proposed driver circuit uses carrier sweep-out effect in the active region when electrical pulse is turned off and peaking effect when electrical pulse is turned on in order to reduce influence of the LED's diffusion capacitance. As the result, it is possible to transmit on-off keying (OOK) signal with speed up to 500 Mb/s.