Towards a high-density photonic tensor core enabled by intensity-modulated microrings and photonic wire bonding

Abstract

We propose a photonic processing unit for high-density analog computation using intensity-modulation-based microring modulators (IM-MRMs). The output signal at the fixed resonance wavelength is directly intensity modulated by changing the extinction ratio (ER) of the IM-MRM . Thanks to the intensity-modulated approach, the proposed photonic processing unit is less sensitive to the inter-channel crosstalk. Simulation results reveal that the proposed design offers a maximum of 17-fold increase in wavelength channel density compared to its wavelength-modulated counterpart. Therefore, a photonic tensor core of size 512 $$\times $$ × 512 can be realized by current foundry lines. A convolutional neural network (CNN) simulator with 6-bit precision is built for handwritten digit recognition task using the proposed modulator. Simulation results show an overall accuracy of 96.76%, when the wavelength channel spacing suffers a 3-dB power penalty. To experimentally validate the system, 1000 dot product operations are carried out with a 4-bit signed system on a co-packaged photonic chip, where optical and electrical I/Os are realized using photonic and electrical wire bonding techniques. Study of the measurement results show a mean squared error (MSE) of 3.09$$\times $$ × 10$$^{-3}$$ - 3 for dot product calculations. The proposed IM-MRM, therefore, renders the crosstalk issue tractable and provides a solution for the development of large-scale optical information processing systems with multiple wavelengths.

Fiber-coupled quantum dot single-photon source via photonic wire bonding

“…In the second step, photonic wire bonds are applied by means of a free-form two-photon polymerization process to interface the quantum dot waveguide single-photon sources and connect them to the individual optical fibers of a commercial V-groove fiber array similar to Ref. [17]. A scanning electron microscopy (SEM) image and an optical micrograph of the photonic wire bond link between a quantum dot waveguide and an optical fiber are shown in Figure 1(a) and (b), respectively.…”

Neuromorphic Photonics Circuits: Contemporary Review

“…Globally, existing photonic structures for the realization of neural network operation, depending on the type of source in the circuit, are divided into two subspecies: coherent and incoherent architectures. The first variant implies that the input light is used in an array of beam splitters and phase shifters to perform matrix computation operations using interference between different paths, i.e., in this variant, it is possible to use a single laser source but with sufficient power [151]. Such an architecture is often built on Mach-Zehnder interferometers [50,152].…”

Plug‐and‐Play Fiber‐Coupled Quantum Dot Single‐Photon Source via Photonic Wire Bonding

“…[24] Furthermore, PWBs have been employed to address the complex packaging requirements of neuromorphic photonic accelerator architectures. [25,26] PWBs are 3D waveguides created by using direct-write twophoton polymerization. [27,28] Therefore, they provide potential superior scalability, making them an attractive alternative to the existing methods.…”

“…[ 24 ] Furthermore, PWBs have been employed to address the complex packaging requirements of neuromorphic photonic accelerator architectures. [ 25,26 ]…”