Sifotonics Technologies Co., Ltd.

Tzung-I Su

Dong Pan

Tuo Shi

Yongbo Shao

Pengfei Cai

Mengyuan Huang

Ching-yin Hong

Yadong Liu

Ning Zhang

Su Li

Wang Chen

Changhua Chen

Te-huang Chiu

Zuoxi Li

Naichuan Zhang

Various embodiments of a coplanar waveguide (CPW) transmission line as well as a silicon-based electro-optic (E-O) modulator comprising the CPW transmission line are described. The CPW transmission line has a curved or winding shape. The silicon-based E-O modulator includes a rib optical waveguide, a beam splitter, a beam combiner, and a CPW transmission line that exhibits the winding shape. At least one of the two optical arms of the rib optical waveguide alternately and periodically extends through a first groove and a second groove of the CPW transmission line. The plurality of active sections of the rib optical waveguide are evenly distributed on both sides of the CPW transmission line to suppress undesired transmission modes. An increased length of transmission path of the rib optical waveguide is also avoided or minimized, thereby reducing the transmission speed mismatch of the E-O modulator, which is essential for achieving high-speed operation.

Coplanar waveguide transmission line and silicon-based electro-optic modulator comprising the same

Various embodiments of a monolithic avalanche photodiode (APD) are described, which may be fabricated on a silicon-on-insulator substrate. The monolithic APD includes an optical waveguide that guides an incident light to an active region of the APD. An optical coupler is integrally formed with the optical waveguide to capture the incident light. The monolithic APD also includes an optical reflector to reflect a portion of the incident light that is not readily captured by the optical coupler back to the optical coupler for further capturing. The active region includes an absorption layer for converting the incident light into a photocurrent, an epitaxial structure for amplifying the photocurrent by avalanche multiplication, as well as a pair of electrical conductors for conducting the amplified photocurrent.

Waveguide-integrated avalanche photodiode

Various embodiments of a monolithic electro-optical (E-O) modulator are described. The monolithic E-O modulator includes an active region comprising a plurality of p-n junction diodes, as well as a modulation electrode and a bias electrode that extend through the active region. The monolithic E-O modulator further includes a resistor-capacitor-bias-capacitor (RCBC) electrode structure configured to receive an electrical modulation signal, a direct-current (DC) bias voltage and a power supply voltage. Specifically, the RCBC electrode structure includes a resistor coupled to the modulation electrode and two capacitors each coupled to a respective end of the bias electrode. Beneficially, the RCBC electrode structure enables the p-n junction diodes to be biased independently from a DC level of the electrical modulation signal.

Monolithic electro-optical modulator having RCBC electrode structure

Various embodiments of a monolithic electro-optical (E-O) modulator are described, which may be fabricated on a silicon-on-insulator substrate. The monolithic E-O modulator includes an optical waveguide that allows an optical signal to propagate therein. The monolithic E-O modulator also includes a comb-shaped transmission line for conducting an electrical modulation signal that modulates the optical signal. The comb-shaped transmission line includes electrical conductors running in parallel with the optical waveguide. At least one of the conductors includes recesses or thin slots that form the conductor into a shape having a plurality of teeth, like a comb. The comb-shaped transmission line can be engineered to realize a close matching between a propagation velocity of the optical signal along the optical waveguide and a group velocity of the electrical modulation signal along the comb-shaped transmission line, which helps to achieve a high operating speed of the monolithic E-O modulator.

Monolithic electro-optical modulator with comb-shaped transmission line

Various embodiments of a photonic integrated circuit (PIC) are described herein. A PIC, functioning as a coherent receiver, may include optical components such as an optical coupler, a directional coupler, a beam splitter, a polarizing beam rotator-splitter, a variable optical attenuator, a monitor photodiode, 90-degree hybrid mixer, and a waveguide photodiode. The PIC may also include electrical components such as an electrode, a capacitor, a resistor and a Zener diode.

Silicon photonic integrated circuit with electrostatic discharge protection

Various embodiments of a monolithic electro-optical (E-O) modulator are described herein. The monolithic E-O modulator may include a phase shifter having a suspended structure. The suspended structure may be realized by partially or completely removing silicon material underneath the active area of the phase shifter to form a void in the bulk silicon substrate supporting the phase shifter. The suspended structure may be utilized to result in a lower radio-frequency loss and an effective group refractive index of the phase shifter that is closer to the refractive index of silicon waveguides or optical fibers, both advantageous to enhancing the performance of the E-O modulator such as a higher operating bandwidth.

Monolithic electro-optical modulator having suspended structure

Silicon photonic integrated circuit with electrostatic discharge protection mechanism for static electric shocks

Various embodiments of a fully integrated avalanche photodiode receiver and manufacturing method thereof are described herein. A photonic device includes a silicon-on-insulator (SOI) substrate with a buried oxide (BOX) layer therein, an avalanche photodiode integrated with the SOI substrate, a capacitor integrated with the SOI substrate, a resistor integrated with the SOI substrate, and silicon passive waveguides as well as bonding pads integrated with the SOI substrate.

Fully integrated avalanche photodiode receiver

Various embodiments of a compensated photonic device structure and fabrication method thereof are described herein. A photonic device may include a silicon-on-insulator (SOI) substrate with a buried oxide (BOX) layer therein, a Si waveguide and an n-type contact layer formed on the BOX layer, a Si multiplication layer disposed on the n-type contact layer, a p-type Si charge layer disposed on the Si multiplication layer, a germanium (Ge) absorption layer disposed on the p-type Si charge layer, a p-type contact layer disposed on the Ge absorption layer, and a metal layer disposed on the p-type contact layer. A compensated region may be formed between the p-type Si charge layer and the Ge absorption layer with a portion of the compensated region in the p-type Si charge layer and another portion of the compensated region in the Ge absorption layer.

Compensated photonic device structure and fabrication method thereof

An optical coupler structure may include a substrate, a waveguide section and an anchored cantilever section. The substrate may include a main body and a sub-pillar structure formed on the main body. The waveguide section may be disposed on the substrate, and may include a core waveguide of a first material surrounded by a cladding layer of a second material. The anchored cantilever section may be disposed on the sub-pillar structure on the substrate, which may be configured to support the cantilever section and separate the cantilever section from the main body of the substrate. The anchored cantilever section may include a multi-stage inverse taper core waveguide and a cladding layer, of the second material, which surrounds the multi-stage inverse taper core waveguide.

Optical coupler having anchored cantilever structure with multi-stage inverse taper core waveguide and fabrication method thereof

A compact and highly efficient coupling structure for coupling between DFB-LD and Si PIC edge coupler with suppressed return loss may include a DFB-LD, a Si PIC comprising at least one input edge coupler and at least one output edge coupler, a silica cover lid disposed on the Si PIC and aligned edge to edge with the Si PIC, a single-mode fiber aligned to the at least one output edge coupler of the Si PIC, a lens disposed between the DFB-LD and the at least one input edge coupler of the Si PIC, and an isolator bonded to a facet of the at least one input edge coupler with a first volume of an index matching fluid. The lens may be configured to minimize a mismatch between an output spot size of the DFB-LD and a spot size of the at least one input edge coupler of the Si PIC.

Low return loss silicon photonics package structure

A ring optical modulator includes a SOI substrate, including at least first and second top silicon layers, and a silicon-based ring resonator formed on the SOI substrate. The silicon-based ring resonator includes first and second top silicon layers, a thin dielectric gate layer disposed between the top silicon layers, first and second electric contacts, and first rib-type waveguide and ring-shape rib-type waveguide formed on the second top silicon layer. The thin dielectric layer includes a first side in contact with the first top silicon layer and a second side in contact with the second top silicon layer. With electric signals applied on the electric contacts, free carriers accumulate, deplete or invert within the top silicon layers on the first and second sides of the thin dielectric gate layer beneath the ring-shape rib-type waveguide, simultaneously, and a refractive index of the ring-shape rib-type waveguide confining optical fields is modulated.

Rib-type waveguide silicon modulators and optical devices

An optical package for providing efficient coupling between a distributed feedback laser diode (DFB-LD) and a silicon photonic integrated-circuit chip (Si PIC) edge couplers with low return loss, as well as variations thereof, is described. The optical package may include a DFB-LD, a Si PIC, a single mode fiber or fiber array assembly, a lens and a spacer. The Si PIC may include an input edge coupler and an output edge coupler. The single mode fiber or fiber array assembly may be aligned to the output edge coupler. The lens may be disposed between the DFB-LD and the input edge coupler, and may be configured to minimize a mismatch between an output spot size of the DFB-LD and a spot size of the input edge coupler of the Si PIC. The spacer may be bonded to a facet of the input edge coupler with an index matching fluid.

Optical package providing efficient coupling between DFB-LD and silicon PIC edge couplers with low return loss

Various structures of an electro-optic device and fabrication methods thereof are described. A fabrication method is provided to fabricate an electro-optic device which may include a silicon-based rib-waveguide modulator which includes a first top silicon layer, having a first doped region that is at least partially doped with dopants of a first conducting type, a second top silicon layer, having a second doped region that is at least partially doped with dopants of a second conducting type, and a thin dielectric gate layer disposed between the first top silicon layer and the second top silicon layer. The second doped region may be at least in part directly over the first doped region. The modulator may also include a rib waveguide formed on the second top silicon layer, a first electric contact formed on the first top silicon layer, and a second electric contact formed on the second top silicon layer.

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Taoyuan, Taiwan

Tzung-I Su