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In this paper, we propose and experimentally demonstrate a novel compact multi-port multi-wavelength laser source (MP-MWL) for the optical I/O technology. The multi-wavelength DFB laser array is used for realizing the simultaneous emission of multiple wavelengths. The reconstruction equivalent chirp technique is used to design and fabricate the π-phase shifted DFB laser array to achieve precise wavelength spacing. The number of wavelengths is enlarged through the monolithically integrated wavelength routing architecture (WRA), and 64 optical carriers are obtained with 8 wavelengths in 8 output ports. The proposed MP-MWL has high mode stability and high uniform wavelength spacing. The side mode suppression ratio (SMSR) of each wavelength is more than 40 dB and the wavelength spacing is 100 GHz under 25 °C working environment. A semiconductor optical amplifier (SOA) is monolithically integrated into each output port to amplify the output power. The output power of each port exceeds 15 mW when the current injected into the SOA is 150 mA. Besides, the relative intensity noise (RIN) of all wavelengths is below -130 dB/Hz, and clear 25 Gb/s NRZ eye grams are obtained for the 64 optical carriers with the external lithium-niobate Mach-Zehnder modulator, with a total transmission rate of 1.6 Tbps. The superior performance of the proposed MP-MWL enables it to be a promising approach for the Tbps optical I/O links and high-density chip interconnection system.

To the best of our knowledge, the spectroscopic and highly efficient tunable multi-wavelength laser properties of Er3+,Yb3+,Pr3+ triple-doped BaLaGa3O7 crystals are demonstrated for the first time in this study. The maximum output power of 0.81 W at ∼2.7 μm was obtained under the absorbed pump power of 3.53 W with an optical-to-optical conversion efficiency of 22.9%. The slope efficiency is 27.0%. The results demonstrate that the triple-doped crystals with the sensitizer Yb3+ and deactivator Pr3+ can not only enhance the pump efficiency effectively but also suppress the self-terminating "bottleneck" effect of Er3+ so that the laser threshold is reduced and the laser efficiency is improved. The Er3+,Yb3+,Pr3+ triple-doped BaLaGa3O7 crystal is a promising candidate for high-efficiency mid-infrared laser devices. [ABSTRACT FROM AUTHOR]

We propose and experimentally demonstrate a compact and efficient photonic convolution accelerator based on a hybrid integrated multi-wavelength DFB laser array by photonic wire bonding. The photonic convolution accelerator operates at 60.12 GOPS for one 3 × 3 kernel with a convolution window vertical sliding stride of 1 and generates 500 images of real-time image classification. Furthermore, real-time image classification on the MNIST database of handwritten digits with a prediction accuracy of 93.86% is achieved. This work provides a novel, to the best of our knowledge, compact hybrid integration platform to realize the optical convolutional neural networks.

Multi-wavelength laser absorption spectroscopy has the advantages of superior sensitivity, accuracy, and robustness for gas sensing applications, offering an opportunity for the development of high-performance laser-based hygrothermographs. However, accurate and fast determination of gas parameters from multiple spectral features can be quite challenging in the presence of large numbers of features, measurement noise, and increasing demands for real-time measurements. To address this challenge, we propose a transfer-learning-based multi-wavelength laser absorption sensor for the quantitative and simultaneous measurement of temperature and concentration of water vapor, with a focus on real-time monitoring of ambient temperature and relative humidity (RH). A spectral simulation based on the most-updated HITRAN database was employed as the dataset for model pre-training and transfer learning. The experimental dataset was obtained from absorption measurements using a distributed feedback laser that probed multiple water absorption features within the band of 7179-7186 c m -1 . To evaluate the sensor performance, mean absolute error, error distribution, and linearity were selected. In the presence of an insufficient experimental dataset for direct data training, the proposed transfer learning approach outperformed the traditional deep learning method with a lower prediction error of 0.14°C and 0.42% for temperature and RH, respectively, as compared to the values of 0.84°C and 0.66% obtained using the traditional deep learning method. Finally, the fast data post-processing performance of the proposed transfer learning approach was demonstrated in a field test against the conventional baseline fitting method.

This work presents a simple microwave photonic downconversion channelizer based on multi-wavelength laser sources. The design of two laser diode (LD) arrays enables signal multiplexing and simultaneous multichannel downconversion processing, which provide stable, relatively flat, and strong multi-frequency combs. A proof-of-concept experiment was taken, showing that 14.375-17.75 GHz broadband radio frequency (RF) signals were successfully downconverted to the same intermediate frequency (IF) and were sliced into four subchannels with 875 MHz bandwidth showing excellent image rejection and channel uniformity, which agrees with the simulation results. The spurious free dynamic range (SFDR) of the proposed RF channelizer is 100 d B H z 2/3 , the image rejection is over 28 dB, and the frequency measurement error is less than ±6 M H z . Replacing optical filters with electrical filters, the proposed simple optoelectronic hybrid reconfigurable microwave photonic channelizer system acquits stable performance and high maturity and meets the application requirements, behaving with stupendous potential in fields such as radar, satellite communication, electronic warfare, and others.

As a new type of photonic‐chip light source, quantum dot (QD) lasers have recently received remarkable attention. However, two significant problems remain to be solved: the high lasing threshold characteristics and the single wavelength application in a photonic chip. To achieve this, a multi‐wavelength quantum dot laser is proposed. An ultrathin QDs‐film laser with a thickness of 78 nm is developed. The microstructure of MAPbBr3 + graphene + CoGaZnS is studied using Raman spectroscopy and simulation, illustrating the different optical bandgap structures in different combinations. Four‐wavelength lasing at 540, 628, 769, and 824 nm with thresholds of 25 kW cm–2 and 50 kW cm–2 are achieved at room temperature. The finite‐difference time‐domain (FDTD) simulation results suggest a photon‐jumping phenomenon in a fixed period. Subsequently, the transient absorption (TA) spectrum of the QDs‐film is measured to reveal the ultrafast photonics process, which proves the two hot‐carrier transfer processes and the zitterbewegung (ZB) phenomenon in graphene at 416 nm. The ZB‐dominated hot‐carrier transfer from perovskite MAPbBr3 to CoGaZnS is confirmed. This study can contribute to hot‐carrier lasing and light‐source research in photonic chips. [ABSTRACT FROM AUTHOR]