This PDF file contains the front matter associated with SPIE Proceedings Volume 12504, including the Title Page, Copyright information, Table of Contents, and Conference Committee Page.

An optical system for scanning angle amplification in tunable laser based all-solid lidar is theoretically analyzed and experimentally demonstrated with θ=51° when tuning the wavelength from 1531.2nm to 1566.6nm. We have achieved 22 points beam-steering which is identical to the tunable laser channels. The device has several microseconds beam switching speed and 1.4° beam divergence. The size of the device is compact which is only 5cm×4.5cm×1.8cm, and the total system is low-cost.

In order to implement the network management and fault location towards cross domain optical networks, pilot tone technology is introduced to the optical modules which are located at both ends of the cross domain network so as to manage and control the remote optical modules. For the hardware based pilot tone circuit design applied on the widely used 100GBASE-LR4 optical modules, we propose to use one specified lane of the four lanes to implement the transmission of pilot tone signal. After unifying the modulation type, coding format and transmission protocols for pilot tone, the optical module can realize the interoperability for both high-speed service and low-frequency pilot tone signals. The experiment results show that the 100GBASE-LR4 optical modules can support 10km transmission with 5dB margin reserved when pilot tone function is enabled and 5% modulation depth is used. Since different modulation depth may lead to receiving sensitivity degradation in terms of Ethernet application, the balancing point of modulation depth and sensitivity need to be concerned at the stage of optical module design aiming to reducing the pilot tone penalty. In addition, as the increasing lane rate of high-speed optical modules that use PAM4 modulation instead of NRZ, how to solve the problem of poor anti-noise performance of PAM4 signal would become an important precondition for the continuous development of next generation of pilot tone technology.

Interleaved modulators enable more optimized doping profiles for higher modulation efficiency and lower loss. Nevertheless, as far as we know, complex doping for interleaved modulators has hardly been studied. Hence this work proposes a modulator based on interleaved vertical and U-shaped junctions using the Monte-Carlo simulation. The results illustrate that the modulation efficiency of the designed interleaved period is 0.57 V·cm, while the loss is 15.5 dB/cm. This high-efficiency design verifies the benefits of interleaved 3D modulator design as significantly increasing modulation efficiency with low loss, showing great potential for high-speed application.

Si-based thermal infrared emitter is one of the key components of the micro NDIR gas sensor. In this paper, a low power, low-cost, and radiation enhanced thermal infrared emitter was developed and fabricated based on a commercial standard CMOS technology. A CuO-MnO2 film with porous structures was deposited on the center of the freestanding membrane of the device by electrohydrodynamic inkjet printing to enhance the infrared emission. The CMOS infrared emitter takes only about 150 mW to reach 500 ℃. The modulation depth is larger than 90% at 10 Hz and about 50% at 50 Hz. Both the emission spectrums and the infrared radiation power results confirmed that the printed radiation enhance layer significantly improved the radiation intensity of the device in a mid-infrared wavelength of 2.5-8 μm. The stability of the devices was tested by studying the resistance drifts of the emitters after operation for a period of time. The emitter shows excellent stability at 450 ℃ and below. The resistance drift of the emitter operating at 500 ℃ was reduced to about half of the unannealed devices by electrothermal annealing at 650 ℃ for 10 min. The CMOS infrared emitter can be easily integrated with CMOS interface circuits in the future to achieve highly integrated smart sensor.

We propose a simple and effective model to properly design the monolithically integrated tunable optical transmitter based on the traveling wave Mach-Zehnder modulator (TW-MZM) and V-cavity laser (VCL). Firstly, the integrated structure of TW-MZM and VCL is presented. Then we put forward a TW-MZM model to design and improve the performance of the electro-optic (EO) modulation bandwidth of the optical transmitter. By changing the structural parameters of the optical waveguide and the traveling wave electrodes, we reduce the microwave transmission loss from 3 mm^-1 to 0.6 mm^-1 at 20 GHz and thus increase the theoretical electro-optic response from 13.5 GHz to 52.8 GHz. Due to the high modulation efficiency from the Quantum Confined Stark Effect (QCSE) in quantum wells, the traveling wave modulator is very compact with a length of only 600 μm.

An on-chip TE-pass polarizer working near 850nm band is designed and fabricated on silicon nitride platform. The structure is very simple, using a straight silicon nitride waveguide separated from a metal strip by a low index silicon oxide spacer layer. By optimizing the thickness of the spacer layer, the metal strip introduces more loss for TM mode than TE mode. The measured extinction ratio of the fabricated device is around 20dB over a 16nm wavelength range from 837nm to 853nm for a 3mm-long polarizer.

On-chip photonic devices are promising for large-scale optical trapping and parallel particle manipulation. Based on a waveguide grating, which can convert light from a localized optical mode to a freely propagating radiation beam, we propose two waveguide-grating-based optical tweezers for trapping micro- and sub-micro-particles. By optimizing the structural parameters of the etched trenches on the waveguide, the intensity distribution of the upward diffraction beam out of the grating is altered to approximate a target beam that can produce large gradient forces. The optimization method generates a focused quasi-Gaussian beam with a waist height of 7 μm above the grating and a beam with quasi-spherical wave wavefronts at ± 20°. The optimized upward radiation beams generate gradient forces up to hundreds of pN/W, which is strong enough for trapping microparticles with a trapping range as high as 20 μm. Besides, the proposed tweezer shows a possibility of trapping sub-micron particles and the potential for large-scale parallel particle manipulation.

On-chip supercontinuum generation has attracted a great deal of attention in recent years. Among silicon-based materials, silicon nitride represents an attractive solution for on-chip supercontinuum generation due to its wide transparency window, relatively high Kerr nonlinearity, and negligible two-photon absorption. In this paper, we achieve a flat allnormal dispersion profile in the silicon nitride platform, with a flat dispersion from 600 nm to 2760 nm. Using the proposed waveguide, an ultra-flat (-6 dB) high-coherent octave-spanning supercontinuum covering from 638 nm to 1477 nm can be generated by launching a 250-fs 30-kW input pulse centered at 960 nm. The proposed supercontinuum is of great importance for achieving high-resolution optical coherence tomography and fully stabilized frequency comb sources.

We propose a compact, low loss 3dB power splitter enabled by silicon columns. The proposed device consists of two curved waveguides and a group of silicon columns on coupling region, compatible with mature CMOS processes. The simulation results show that the device has the beam splitting of 0.5±0.05 in the wave band from 1270 to 1330nm. Moreover, the effective coupling length is only 11.9μm, and the excess loss is less than 0.04dB, which makes the proposed splitter full of potential to be applied in high-density photonic integrated chips.

We demonstrate an erbium-doped aluminum oxide waveguide amplifier with broadband net gain. The atomic layer deposition technique is used to grow the Er³⁺:Al₂O₃. The layer-by-layer deposition allows to tailor the vertical distribution of erbium ions, by which we can change the concentration of erbium ions and prevent the clustering. We characterize the Er³⁺:Al₂O₃ film using spectroscopic ellipsometry, X-ray photoelectron spectroscopy and photoluminescence measurements. Afterwards, on-chip Er³⁺:Al₂O₃ waveguide amplifiers are fabricated. Signal enhancements of 9.6 ± 0.8 dB and 3.5 ± 0.2 dB are achieved at 1532 nm and 1550 nm, respectively, corresponding to a net gain of 4.6 ± 0.4 dB at 1532 nm. We also measure net gain at different signal wavelengths and obtain net gain from 1525 nm to 1580 nm, covering the whole C-band.

In the rapidly evolving fields of silicon photonics, microresonator-based devices have promising applications due to a small footprint, high performance, and low power consumption. However, the frequency of the optical resonator could drift due to the change in the optothermal refractive index. Here, we propose two types of broadband athermal waveguides which are achieved through the mode anti-crossing effect. These waveguides have three zero-thermal-drift wavelengths (ZTDWs), while the previously published structures have no more than two ZTDWs. A polycarbonate (PC)-coated waveguide shows a small effective thermo-optical coefficient (TOC) variation of ±1.5×10-6 /K from 1350 to 1790 nm. For the TiO2-coated waveguide, the effective TOC has a variation of ±1.5×10^-6 /K from 1510 to 2090 nm. The temperature depended wavelength shift (TDWS) of both microring resonators with a radius of 100 μm has a variation of ±1 pm/K. Both athermal microring resonators show a low bending loss and stable broadband athermal property at longer wavelengths. The highly stable broadband athermal performance of microring resonators will greatly expand the applications in optical communications and sensing systems.

We present a wavelength multiplexing and polarization multiplexing device assisted by subwavelength grating (SWG), implemented on a 300-nm-tall silicon nitride (SiN) platform. The multiplexing device consists of three SiN waveguides- WG₁, WG₂ and WG₃. The bridging waveguide WG₂ between WG₁ and output waveguide WG₃ is designed into SWG structure, which executes the mode coupling thus multiplexing functions according to the principle of phase matching. The results are as follows: for wavelength multiplexing, the insertion loss (IL) is 0.54 dB and 0.58 dB at the center wavelength of O-band and C-band, which is 1310 nm and 1550 nm, respectively. The crosstalk (CT) is -12.5 dB and -23 dB at these two wavelength. The 1-dB bandwidth is larger than 170 nm for both bands. For polarization multiplexing, the IL is 0.44 dB and 0.64 dB at the wavelength of 1310 nm and 1550 nm, with the crosstalk lower than -16.2 dB and -22.8 dB. The 1-dB bandwidth is larger than 180 nm for the two bands.