Applying various functional materials to silicon to enhance the functionality of silicon photonics is a potential solution for silicon photonics platform under the requirement of CMOS compatibility. In this paper, two LN heterogeneous integration platforms have been proposed. One is the integration of LN film with a 220 nm top silicon SOI platform, in which the simulated results demonstrate that the designed modulator has a low half wave-voltage length product of 2.27 V·cm. And the other is the integration of LN film with a 400 nm top silicon nitride on insulator platform, in which the the proposed device achieves a VpiL of 2.58 V·cm and a 3-dB bandwidth of ~130 GHz with 7-mm long modulation region is verified by simulation.
The degenerate mode interaction can possess a clear avoided mode crossing to manipulate the cavity mode spectra by a mode-splitting process under a strong mode-coupling condition in high-Q microresonators. Here, the mode splitting strength can be changed by controlling the pump-resonance effective detuning in a dispersion-managed Si3N4 microresonator through a differential thermo-optic effect. The splitting mode can locally facilitate the frequency matching in normal dispersion microresonators so that the tunable parametric oscillation can be observed by tuning pump-resonance detuning. A broadly tunable THz wave radiation is generated after injecting the tunable parametric oscillation into a bias-free photomixer at room temperature.
We report the demonstration of Si-based waveguide Ge1-xSnx photodetector (PD) at L-band (1565-1625 nm), U-band (1625-1675 nm), and 2μm light detection, optical and electrical properties are studied by using simulation models. With introduction of 4.5% Sn into Ge, the GeSn waveguide PD with evanescent coupling exhibits a high responsivity of 1.25 A/W, dark current is lower than 12 nA. This work provides a new choice for future infrared detection, beneficial to needs of broadband spectrum communication, and compatible with CMOS circuits.
A compact and broadband optical 90° hybrid based on a 2×4 multimode interference (MMI) coupler using the Si3N4 technology is proposed. The effects of MMI length, width, and wavelength on optical power transmission are investigated. With the length of 217 μm for the 2×4 MMI coupler, this optical 90° hybrid shows a maximum phase error of 5°, an excess loss of 1 dB, and a transmission imbalance of 1 dB over a 75-nm-wide wavelength range.
The 3D photonic integrated structure can increase the integration density of the device on a limited chip area, so that the chip has a higher optical interconnection capability. A polarization beam splitter (PBS) is one of the key components for manipulating different polarization states in the areas of optical interconnection and communication. In this paper, a novel interlayer PBS based on an asymmetrical directional coupler (DC) was proposed, which consists of a silicon rib waveguide (WG) and a silicon nitride (Si3N4) strip WG with a gap of 850 nm. By carefully adjusting the geometric parameters of the DC, the phase matching condition between these two WGs can be satisfied for the TM polarization, while the coupling efficiency of the TE polarization is frustrated due to the large phase mismatch. By adding a filter to the thru port the performance of the proposed PBS is improved. The device with a 220 nm Silicon-On-Insulator (SOI) WG and a 700 nm × 400 nm Si3N4 WG operates in a broadband width of 100 nm, with an extinction ratio (ER) <20 dB. The insertion losses (ILs) are <0.22 dB for both TE and TM polarizations at a wavelength of 1550 nm. At the same time, our design parameters conform to the Multi Project Wafer (MPW) process conditions, and the device is highly implementable. The device is potential to use for the on-chip 3D optical interconnect in the future.
Reducing the size of devices and the loss of waveguides are two significant research contents in integrated optics. Surface plasmon polariton (SPP) waveguides can break the diffraction limit and provide tight light confinement, however, they are subject to unavoidable high propagation loss due to the metallic ohmic loss. Traditional dielectric waveguides can propagate light with ultralow loss, but they are subject to the diffraction limit in each direction which will result in large mode size. In general, mode size and loss of waveguides are mutually restricted. Here, we proposed an all-dielectric nanowire waveguide which can confine light into nanoscale gap region and realize deep subwavelength mode confinement in two dimensions. A normalized mode area of 1.4×10-2 is achieved, which keeps on the same level with the plasmonic waveguides. The strong mode confinement is attributed to the discontinuity of the normal component of electric field at the interface of two materials. We determined the supported mode of the all-dielectric nanowire waveguide is quasi-TM mode by analyzing the electric vector distributions. The quasi-TM eigenmode is lossless in theory because of no metal components, which is consistent with our simulation results. The lossless propagation in theory is a significant breakthrough compared to the plasmonic waveguides. The all-dielectric nanowire waveguide realizes both subwavelength mode confinement and low-loss propagation simultaneously, conquers the trade-off between mode size and loss of waveguides in theory.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.