Method of in-wafer testing of monolithic photonic integrated circuits (PICs) formed in a semiconductor wafer

A method of in-wafer testing of monolithic photonic integrated circuits (PICs) formed in a semiconductor wafer, each circuit comprising an array of integrated laser sources and an array of integrated electro-optic modulators, one each for each of the laser sources, and an optical combiner to receive the modulated signal outputs from each of the electro-optic modulators comprising the steps of:

• providing a first integrated photodetector at a rear facet of each of said laser sources in each circuit;
• providing a second integrated photodetector between each of said modulators and said optical combiner in each circuit;
• sequentially operating each of the laser sources in a selected circuit to monitor light output from a laser source via its first corresponding photodetector and calibrate its operating characteristics by detecting the laser source output via its second corresponding photodetector thereby providing first calibration data;
• sequentially operating each of the modulators in the selected circuit to monitor signal output from a modulator via its second corresponding photodetector and adjusting its bias point of operation to achieve optimum extinsion ratio and chirp thereby providing second calibration data;
• and
• thereafter storing the first and second calibration data for each circuit for future reference.

A method of in-wafer testing of monolithic photonic integrated circuit (PICs) formed in a semiconductor wafer, each circuit comprising an array of integrated laser sources and an array of integrated electro-optic modulators, one each for each of the laser sources, and an optical combiner to receive the modulated signal outputs from each of the electro-optic modulators comprising the steps of:

• providing an integrated photodetector between each of said laser sources and said modulators or between said modulators and said optical combiner in each circuit;
• sequentially operating each of the laser sources in a selected chip to monitor light output from a laser source via its corresponding photodetector and calibrate its operating characteristics by detecting the laser source output via its corresponding photodetectors;
• sequentially operating each of the modulators in the selected chip to monitor signal output from a modulator via its corresponding photodetector and adjusting its bias point of operation to achieve optimum extinsion ratio and chirp thereby providing calibration data relating to the circuit;
• and
• thereafter storing the calibration data for each circuit for future reference.