Chip-based advanced modulation format transmitter
View Patent ↗In various embodiments, a monolithic integrated transmitter, comprising an on-chip laser source and a modulator structure capable of generating advanced modulation format signals based on amplitude and phase modulation are described.
1. A monolithically integrated optical transmitter comprising:
at least one monocrystalline substrate;
a tunable laser resonator monolithically integrated with the substrate;
a first and a second modulator monolithically integrated with the substrate, the first and second modulators configured to modulate intensity and phase of an input optical signal and produce a modulated optical signal;
a polarization rotator monolithically integrated with the substrate; and
an optical combiner monolithically integrated with the substrate and configured to combine optical signals output from the first and second modulators, the optical combiner including a first input waveguide connected to the first modulator, a second input waveguide connected to the second modulator and at least one turning mirror disposed with respect to the first or second input waveguides, the polarization rotator disposed in the optical path between the first or second modulator and the optical combiner, the modulated optical signal from the first or second modulator being coupled into the polarization rotator.
2. The optical transmitter of claim 1 , wherein the substrate comprises at least one of Si, InP, InAlGaAs, InGaAsP, InGaP, GaAs or InGaAs.
3. The optical transmitter of claim 1 , wherein the turning mirror has at least one reflective facet that is arranged at an angle with respect to the first or the second input waveguides.
4. The optical receiver of claim 1 , wherein the turning mirror is configured to change the direction of propagation of optical radiation in the first or the second input waveguides by an angle.
5. The optical receiver of claim 4 , wherein the angle is between approximately 90 degrees and approximately 180 degrees.
6. The optical transmitter of claim 1 , configured to generate a QPSK modulated optical signal.
7. The optical transmitter of claim 1 , configured to generate a QAM modulated optical signal.
8. The optical transmitter of claim 1 , wherein at least one of the first and second modulators comprises a dual nested Mach-Zehnder modulator.
9. The optical transmitter of claim 1 , wherein each of the first and the second modulators comprises at least one electrode.
10. The optical transmitter of claim 9 , wherein each of the first and the second optical modulators comprises at least four electrodes.
11. The optical transmitter of claim 10 , further comprising a feedback circuit configured to provide an input electrical signal to the first or second optical modulators based on an output of the one or more monitor electrodes.
12. The optical transmitter of claim 1 , further comprising one or more monitor electrodes configured to monitor power of the modulated optical signal at the output of the first or second optical modulator.