Patent ID: 11874582
Assignee: SHANGHAI JIAO TONG UNIVERSITY
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 1:
2. A method for manufacturing the monolithically integrated optical analog-to-digital conversion system as described in claim 1, comprising:
(1) preparation of waveguide structures (711):
composing the lithium niobate-silicon wafer of a substrate layer (740), a silicon dioxide layer (730), a lithium niobate layer (720), and a silicon layer (710) from bottom to top;
providing the waveguide structures (711) on the silicon layer (710), the uppermost of the lithium niobate-silicon wafer, the waveguide structures (711) comprising an optical splitter, a beam combiner, a phase shift straight waveguide, and the optical input and output ports of the electro-optical modulator array (100), delay waveguides, a thermo-optical switch, and the optical input and output ports of the tunable delay line array (200), and the optical input ports of the photoelectric detector array (300), and determining process parameters of exposure time according to respective widths and heights of corresponding different waveguides; and
connecting the waveguides according to the connections between the optical output ports of the electro-optical modulator array (100) and the optical input ports of the tunable delay line array (200) and between the optical output ports of the tunable delay line array (200) and the optical input ports of the photoelectric detector array (300) as described in claim 1, manufacturing a mask plate according to the connections, and etching the silicon layer through a standard CMOS process to form the waveguide structures (711);
(2) preparation of a germanium film active area of the photoelectric detector array:
depositing a germanium film on the top of the lithium niobate-silicon wafer through a chemical vapor deposition method on a basis of step (1),
etching the germanium film through a CMOS process, reserving one piece of germanium film behind the optical input port of each of the 2n silicon-germanium photoelectric detectors as an active area (712), and
removing the rest of the germanium film, each piece of the germanium film active area (712) behind the optical input port of each of the 2n silicon-germanium photoelectric detectors covering a section of the waveguide, so that light entering through the optical input port is converted into electric signals when reaching the active area (712);
(3) formation of an electronic circuit:
protecting the electro-optical modulator array (100), the tunable delay line array (200), and the photoelectric detector array (300) formed in steps (1) and (2) with photoresist or a deposited protective material (713), and forming electronic devices (714) required in the system through a standard CMOS process, the electronic devices (714) comprising the clock (401), the frequency multiplier group (402), the frequency divider group (403), the filter group (404), the phase shifter group (405), and an amplifier group (406) in the radio-frequency drive circuit (400), the direct-current drive circuit (500), and the electronic signal processing circuit (600); and
(4) preparation of all electrodes (715) and electrical interconnection lines (717):
forming all electrodes of the electro-optical modulator array (100), all electrodes of the tunable delay line array (200), and all electrodes of the photoelectric detector array (300);
forming the electrical interconnection line between all the electrodes of the photoelectric detector array (300) and the electronic signal processing circuit (600),
forming the electrical interconnection line between the radio-frequency drive circuit (400) and the electro-optical modulator array (100),
forming the electrical interconnection lines of the direct-current drive array (500) with the electro-optical modulator array (100), the tunable delay line array (200), and the photoelectric detector array (300),
forming the electrical interconnection line for the sampling gate (101) to receive the analog signal input from the outside out of the monolithically integrated optical analog-to-digital conversion system, and
forming the electrical interconnection line for the electronic signal processing circuit (600) to output the digital signals to the outside;
etching to remove the protective layer first and depositing an electrode material in the plane of the waveguide in a case of the photonic device array with the protective layer;
etching to form through-holes (716) first and depositing an electrode material to a position communicated with the electronic devices in a case of the electronic devices with the protective layer; and
completing the preparation of all the electric interconnection lines (717).