Transmitter photonic integrated circuit (TxPIC) chip
A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.
1. A semiconductor chip having an output facet, the semiconductor chip comprising:
a light source provided on the semiconductor chip;
a photo diode provided on the semiconductor chip;
an optical combiner provided on the semiconductor chip, the optical combiner having a first input and a second input, and an output, the first input being coupled to the light source and the second input being coupled to the photodiode, the output providing an output signal through the output facet of the semiconductor chip; and
a coating provided on the output facet of the semiconductor chip, wherein a portion of the output signal is reflected by the output facet, the reflected portion of the output signal passing through the optical combiner and being output through the second input of the optical combiner to the photo detector, a thickness of the coating being one of a plurality of thicknesses, each of the plurality of thicknesses being associated with a corresponding one of a plurality of intensities of the reflected portion of the output signal, the thickness of the coating being associated with one of the plurality of intensities which is less than remaining ones of the plurality of intensities.
2. The semiconductor chip of claim 1 wherein a minimal value of received light comprises light received from an optical link coupled to the output facet of the semiconductor chip.
3. The semiconductor chip of claim 1 wherein the second input of the optical combiner is higher order Brillouin zone input of the optical combiner.
4. A method of manufacturing an optical device, comprising the steps of:
providing an electro-optic component, a waveguide, an optical combiner and a photo diode on a semiconductor chip, the semiconductor chip including an output facet, the waveguide being coupled to the output facet and the optical combiner, the optical combiner having a first input coupled to the electro-optic component and a second input coupled to the photodiode;
transmitting an output signal on the waveguide from the optical combiner to the output facet, wherein a portion of the output signal is reflected by the output facet, the reflected portion of the output signal passing through the optical combiner and being output through the second input to the photodetector;
measuring a plurality of intensities of the reflected portion of the output signal received by the photo detector;
depositing a coating on the output facet during the measuring of the plurality of intensities; and
terminating the coating deposition when one of the plurality of measured intensities is less than remaining ones of the plurality of measured intensities.
5. The method of claim 4 wherein the electro-optic component comprises a directly modulated laser diode or a laser diode and an electro-optic modulator.
6. The method of claim 4 wherein the combiner is a wavelength selective multiplexer.
7. The method of claim 6 wherein the wavelength selective multiplexer is an arrayed waveguide grating or an Echelle grating.
8. The method of claim 4 wherein the second input of the optical combiner is a higher order Brillouin zone input of the optical combiner.