Packaged 40 Gb/s Backslot Type LiNbO_3 Optical Modulator with a Low-driving-voltage of 2.8V

摘要

We propose a newly designed X-cut lithium niobate (LiNbO3) optical modulator. It has a two-step back-slot structure to satisfy the velocity matching condition without the buffer layer of silicon dioxide (SiO2). Accordingly, this modulator can achieve low drive voltage and low optical insertion loss. In addition, de-drift phenomena due to the buffer layer can be suppressed. This structure is fabricated with micro-machining technology using excimer laser ablation. The optical 3-dBe bandwidth of fabricated modulator reaches 30GHz and the drive voltage is less than 3V at 1kHz. From the measurement of optical eye diagram at 43.5-Gb/s, the RF-extinction-ratio resulted in 12dB with the drive voltage of 4.1Vp-p. This modulator has the sufficient capability for 40-Gb/s optical transmission systems.