Ultrahigh-resolution on-chip spectrometer with silicon photonic resonators

A compact spectrometer on silicon is proposed and demonstrated with an ultrahigh resolution.It consists of a thermally-tunable ultra-high-Q resonator aiming at ultrahigh resolution and an array of wideband resonators for achieving a broadened working window.The present on-chip spectrometer has a footprint as compact as 0.35 mm^(2),and is realized with standard multi-project-wafer foundry processes.The measurement results show that the on-chip spectrometer has an ultra-high resolution Δλ of 5 pm and a wide working window of 10 nm.The dynamic range defined as the ratio of the working window and the wavelength resolution is as large as 1940,which is the largest for on-chip dispersive spectro-meters to the best of our knowledge.The present high-performance on-chip spectrometer has great potential for high-resolution spectrum measurement in the applications of gas sensing,food monitoring,health analysis,etc.

Silicon photonic spectrometer with multiple customized wavelength bands

A silicon photonic spectrometer with multiple customized wavelength bands is developed by introducing multiple channels of wideband optical filters based on multimode waveguide gratings(MWGs)for pre-filtering and the corresponding thermally tunable narrowband filter for high resolution.For these multiple customized wavelength bands,the central wavelengths,bandwidths,and resolutions are designed flexibly as desired,so that the system is simplified and the footprint is minimized for several practical applications(e.g.,gas sensing).A customized silicon photonic spectrometer is designed and demonstrated experimentally with four wavelength bands centered around1310 nm,1560 nm,1570 nm,and 1930 nm,which is,to the best of our knowledge,the first on-chip spectrometer available for sensing multiple gas components like HF,CO,H_(2)S,and CO_(2).The spectral resolutions of the four wavelength bands are 0.11 nm,0.08 nm,0.08 nm,and 0.37 nm,respectively.Such a customized silicon photonic spectrometer shows great potential for various applications,including gas monitors,wearable biosensors,and portable spectral-domain optical coherence tomography.

First demonstration of an on-chip quadplexer for passive optical network systems

An on-chip quadplexer is proposed and demonstrated with four wavelength-channels of 1270, 1310, 1490, and 1577 nm. The present quadplexer consists of four cascaded filters based on multimode waveguide grating(MWG), which are composed of a two-mode(de)multiplexer and an MWG. For the fabricated quadplexer on silicon, all four wavelength channels have flat-top responses with low excess losses of <0.5 dB as well as the desired bandwidths, which are about 16, 38, 19, and 6 nm, respectively. The cross-talk for both upstream channels and downstream channels is less than -24 dB. Moreover, the data transmission of 10 Gb∕s of the present silicon quadplexer is also successfully demonstrated.

Reconfigurable multichannel amplitude equalizer based on cascaded silicon photonic microrings

A compact on-chip reconfigurable multichannel amplitude equalizer based on cascaded elliptical microrings is proposed and demonstrated experimentally.With the optimized structure of the elliptical microring with adiabatically varied radii/widths,the average excess loss for each channel in the initialized state is measured to be less than 0.5 d B,while the attenuation dynamic range can be over 20 d B.Flexible tunability through the overlapping of the resonance peaks of adjacent wavelength-channels enables even higher attenuation dynamic ranges up to50 d B.Leveraging the thermo-optic effect and fine wavelength-tuning linearity,precise tuning of the resonance peak can be implemented,enabling dynamic power equalization of each wavelength-channel in wavelengthdivision-multiplexing(WDM)systems and optical frequency combs.The proposed architecture exhibits excellent scalability,which can facilitate the development of long-haul optical transport networks and high-capacity neuromorphic computing systems,while improving the overall performance of optical signals in WDM-related systems.