RESUMO
We report a Ta2O5 photonic platform with a propagation loss of 0.49â dB/cm at 1550â nm, of 0.86â dB/cm at 780â nm, and of 3.76â dB/cm at 2000 nm. The thermal bistability measurement is conducted in the entire C-band for the first time to reveal the absorption loss of Ta2O5 waveguides, offering guidelines for further reduction of the waveguide loss. We also characterize the Ta2O5 waveguide temperature response, which shows favorable thermal stability. The fabrication process temperature is below 350°C, which is friendly to integration with active optoelectronic components.
RESUMO
The mid-infrared (MIR) region is attracting increasing interest for on-chip synchronous detection and free-space optical (FSO) communications. For such applications, a high-performance electro-optical modulator is a crucial component. In this regard, we propose and investigate a graphene-based electro-absorption modulator (EAM) and microring modulator (MRM) using the suspended germanium waveguide platform. The modulators are designed for the second atmospheric window (8 to 12â µm). The incorporation of double-layer graphene on the suspended slot waveguide structure allows for the significant enhancement of light-graphene interaction, theoretically achieving a 3-dB bandwidth as high as 78â GHz. The EAM shows a calculated modulation depth of 0.022-0.045â dB/µm for the whole operation wavelength range. The MRM exhibits a calculated extinction ratio as high as 68.9â dB and a modulation efficiency of 0.59â V·cm around 9 µm. These modulators hold promise for constructing high-speed FSO communication and on-chip spectroscopic detection systems in the MIR atmospheric window.
RESUMO
The 2-µm waveband is becoming an emerging window for next-generation high-speed optical communication. To enable on-chip high-speed data transmission, improving the signal-to-noise ratio (SNR) by suppressing the coupling loss of a silicon chip is critical. Here, we report grating couplers for TE and TM polarized light at the 2-µm waveband. With a single-step fully etched process on the 340â nm silicon-on-insulator (SOI) platform, the devices experimentally demonstrate high coupling efficiency of -4.0â dB and 1-dB bandwidth of 70â nm for the TE polarized light, while -4.5â dB coupling efficiency and 58â nm 1-dB bandwidth for the TM polarized light. For comprehensive performance, both of them are among the best grating couplers operating in the 2-µm waveband so far. We also demonstrate 81Gbps high-speed on-chip data transmission using pulse amplitude modulation 8-level (PAM-8) signals.
RESUMO
The 3 dB power splitters are fundamental building blocks for integrated photonic devices. As data capacity requirements continue to rise, there is a growing interest in integrated devices that can accommodate multiple spectral bands, including the conventional O-, C-, and L-bands, and the emerging 2 µm band. Here we propose and experimentally demonstrate a 3 dB power splitter based on adiabatic mode evolution using a thin-film lithium niobate, with ultra-broadband operation bandwidth from 1200 to 2100â nm. The fabricated power splitter exhibits low insertion losses of 0.2, 0.16, and 0.53â dB for wavelengths at 1310, 1550, and 2000 nm, respectively. The measured 1 dB bandwidth covers 1260-1360, 1480-1640, and 1930-2030 nm, which we believe that the proposed device is capable of operating in both O-, C-, L-, and 2 µm bands.
RESUMO
In this work, we experimentally demonstrate a passband filter for the 2-µm wave band on the silicon-on-insulator platform. The device consists of a strip waveguide and an apodized subwavelength-structured waveguide. Fabricated on a 340-nm-thick silicon membrane, the proposed passband filter shows a 3-dB bandwidth of 16-33â nm, a high sidelobe suppression ratio (SLSR) of 24â dB, and a low insertion loss (IL) of 0.4â dB.
RESUMO
Multimode interference (MMI)-based power splitters are fundamental building blocks for integrated photonic devices consisting of an interferometer structure. In order to forestall the 'capacity crunch' in optical communications, integrated devices capable of operating in multiple spectral bands (e.g., the conventional telecom window and the emerging 2 µm wave band) have been proposed and are attracting increasing interest. Here, we demonstrate for the first time, to the best of our knowledge, the realization of a dual-band MMI-based 3 dB power splitter operating at the 1.55 and 2 µm wave bands. The fabricated power splitter exhibits low excess losses of 0.21â dB and 0.32â dB with 1 dB bandwidths for 1500-1600â nm and 1979-2050 nm, respectively.
RESUMO
We propose an on-chip transverse magnetic (TM)-pass polarizer utilizing one-dimensional photonic crystals for multi-band operation. The TE0 modes in the 1550/2000nm wave band are suppressed by carefully selecting the pitch lengths of the nanoholes, leveraging the bandgap of the nanohole array. Conversely, the TM0 modes remain almost unaffected. The TM-pass polarizer employs a single-etched design on a standard 220â nm SOI platform and has a compact length of â¼ 17.9â µm. The simulated bandwidths (BWs) for polarization extinction ratios (PERs) > 20â dB and > 25â dB are about 210â nm and 195â nm for the 1550â nm wave band, and 265â nm and 240â nm for the 2000nm wave band. Moreover, the insertion losses (ILs) are â¼ 0.5/0.3â dB at wavelengths of 1550/2000nm, respectively. For the fabricated device, the measured BWs for PER > 20â dB and > 25â dB are evaluated to be larger than 100â nm for both 1550/2000nm wave bands. The measured ILs are 1/0.8â dB at wavelengths of 1550/2000nm. This straightforward and compatible design opens possibilities for the development of practical multi-band silicon photonic integrated circuits.
RESUMO
The 2â µm wavelength band has proven to be a promising candidate for the next communication window. Wavelength-division multiplexing (WDM) transmission at 2â µm can greatly increase the capacity of optical communication systems. Here, we experimentally demonstrate a high-performance silicon photonic flat-top 8-channel WDM (de)multiplexer based on cascaded Mach-Zehnder interferometers for the 2 µm wavelength band. A three-stage-coupler scheme is utilized to provide passbands and reduce channel crosstalk, and 11 thermo-optic phase shifters have allowed active compensation of waveguide phase errors. The fabricated device shows low insertion loss (< 0.9â dB), channel crosstalk (< 20.6â dB) and 1-dB bandwidth of 2.3â nm for operating wavelength ranging from 1955nm to 1985nm. The demonstrated (de)multiplexer could potentially be used for WDM optical data communication in the 2â µm spectral band.
RESUMO
This publisher's note contains a correction to [Opt. Express30, 28232 (2022)10.1364/OE.467473].
RESUMO
Diffractive periodic-structure-based grating couplers (GCs) are the most widely used devices for light coupling between optical fibers and integrated photonic devices. However, conventional GCs have limited wavelength operation and are polarization specific, which is due to the intrinsic radiation angle dependency on both wavelength and polarization. Here we propose and experimentally demonstrate a polarization-splitting dual-band grating coupler (PS-DBGC) for polarization diversity and wavelength division (de)multiplexing (WDM) operation. The four-port two-dimensional PS-DBGC is based on a periodically arranged structure with square holes, and requires only a single etch step in a 340-nm silicon-on-insulator platform. The simulation predicts that the maximum coupling efficiency (CE) of the proposed PS-DBGC is -2.8 dB and -4.6 dB for the O- and C-band, respectively. The measured peak CEs of the fabricated device are -4.7 dB at 1280 nm and -8.4 dB at 1522 nm. We anticipate that this PS-DBGC could potentially improve the performance of any future integrated WDM passive optical network.