On-chip integratable all-optical quantizer using cascaded step-size MMI

Abstract

We propose a novel all-optical phase shifted quantizer using cascade step-size MMI. The operation principle has been derived in detail. A 3-bit quantizer and a 5-bit quantizer are designed and simulated based on 220-nm SOI platform to verify the feasibility of the scheme, of which the lengths are all below 200 μm. To the best of our knowledge, they have the most compact footprint compared to the existing all-optical quantizers. In the end, the fabrication error analyses of the proposed quantizers are carried out to verify their stability.

ADVANCED PROGRESS ON Χ<SUP>(3)</SUP> NONLINEARITY IN CHIP-SCALE PHOTONIC PLATFORMS (INVITED REVIEW)

“…The effective resolution of traditional electrical ADCs will be severely degraded if the sampling rate is several tens of gigahertz. The development of mode-locked laser sources with ultralow timing jitter (several and even sub-femtoseconds) avoids the trade-off by means of photonic ADC, which uses optical sampling and quantization [194][195][196]. While traditional electrical ADC has limited response time and bandwidth, photonic ADC can avoid these inherent electronic bottlenecks and is a promising method for future high-speed signal processing [197].…”

Photonic sampled and quantized analog-to-digital converters on thin-film lithium niobate platform

“…In recent years, many optical ADC schemes have been proposed and demonstrated, which can be divided into four major types [1]: photonic assisted (PA) ADC [3,4], photonic sampled (PS) ADC [2,5,6], photonic quantized (PQ) ADC [7] and photonic sampled and quantized (PSQ) ADC [8][9][10][11][12][13][14][15][16][17]27]. PA, PS and PQ ADCs still require several high speed electronic ADCs for either sampling or quantizing, resulting in additional power consumption and system complexity.…”

“…PA, PS and PQ ADCs still require several high speed electronic ADCs for either sampling or quantizing, resulting in additional power consumption and system complexity. The PSQ scheme, which performs sampling and quantization both in the optical domain, can avoid these problems and has attracted much attention in recent years [8][9][10][11][12][13][14][15][16][17]27]. PSQ ADC can be further subdivided into two broad categories by different quantization methods: optical amplitude quantization (OAQ) schemes [10][11][12][13] and phase-shifted optical quantization (PSOQ) schemes [8,9,[14][15][16][17]27].…”

“…The PSQ scheme, which performs sampling and quantization both in the optical domain, can avoid these problems and has attracted much attention in recent years [8][9][10][11][12][13][14][15][16][17]27]. PSQ ADC can be further subdivided into two broad categories by different quantization methods: optical amplitude quantization (OAQ) schemes [10][11][12][13] and phase-shifted optical quantization (PSOQ) schemes [8,9,[14][15][16][17]27]. In OAQ schemes, different optical amplitude was distinguished via high optical nonlinearities .…”

“…Compared with the OAQ schemes, the above-mentioned PSOQ schemes effectively reduced the input optical power, but they still used discrete devices. In order to achieve an on-chip integration and further downsize the footprint of the system, a quantization approach using a 3×5 step-size multimode interference (MMI) coupler was proposed [16]. The scheme in Ref.…”