High Optical Power, High Gain and High Dynamic Range Directly Modulated Optical Link

In order to achieve a high output power, high gain and high dynamic range directly modulated optical link, we have developed a high power and low noise DFB laser and a high power handling and high efficiency photodiode with specific designs. The laser exhibits high power (180 mW), high efficiency (0.4 W/A), low RIN and a 7.4 GHz modulation bandwidth. The UTC photodiode offers high efficiency (1 A/W), high saturation current (90 mA) and 15 GHz modulation bandwidth. We have realized a low loss optical link with no amplifier and no impedance matching network. We have obtained a 7.3 GHz modulation bandwidth link with a gain higher than $-7~{hbox {dB}}$. Third order intermodulation of the devices at various different polarization points has been investigated to deduce the optical link dynamic range. At 2.5 GHz, we have demonstrated an OIP3 of 37 dBm and a SFDR close to 120 ${hbox {dB}} cdot {rm Hz}^{2/3}$.