In the last decade, coherent optical transmission technology has dominated the provision of high-capacity communications in metro and long-haul networks and is expected to expand to short-reach networks such as data center and passive optical networks. Capacities of more than 1.5 Tb/s have been demonstrated for a single wavelength. In-phase/quadrature (IQ) modulation allows information to be encoded in both the phase and amplitude of light (or in-phase and quadrature components) and is typically achieved by nested multiple Mach–Zehnder modulators (MZMs). MZMs have advantages including low chirp, broadband operation, and easy to achieve high-order quadrature amplitude modulation (QAM), but they are typically large and have high RF power consumption and excess losses. A small IQ transmitter with low RF power consumption is therefore in demand for low-cost and highly integrated coherent modules. In this paper, we experimentally demonstrate a directly reflectivity-modulated laser that can potentially achieve this goal. We demonstrate the device on a hybrid silicon/III-V platform, where silicon photonics offers compact components for filters, modulators, and reflectors, and the III-V material provides gain. In principle, the device could inherit the benefits of conventional directly modulated lasers while overcoming their speed limits. We demonstrate 32/50 Gbaud quadrature phase-shifted keying with low bit error ratios and experimentally prove the feasibility of 30 Gbaud 16-QAM.

中文翻译：

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使用直接反射率调制的激光进行同相/正交调制

在过去的十年中，相干光传输技术主导了城域网和长途网络中高容量通信的提供，并且有望扩展到短距离网络，例如数据中心和无源光网络。单个波长的容量已超过1.5 Tb / s。同相/正交（IQ）调制允许信息以光的相位和幅度（或同相和正交分量）进行编码，通常通过嵌套的多个Mach-Zehnder调制器（MZM）来实现。MZM具有低线性调频，宽带工作以及易于实现高阶正交幅度调制（QAM）的优点，但是它们通常很大，具有很高的RF功耗和过多的损耗。因此，需要低成本和高度集成的相干模块的，具有低RF功耗的小型IQ发射机。在本文中，我们通过实验证明了可以直接实现此目标的直接反射调制激光。我们在混合硅/ III-V平台上演示了该设备，其中硅光子学为滤波器，调制器和反射器提供紧凑的组件，而III-V材料提供增益。原则上，该设备可以在克服其速度限制的同时继承传统直接调制激光器的优势。我们演示了具有低误码率的32/50 Gbaud正交相移键控，并通过实验证明了30 Gbaud 16-QAM的可行性。我们通过实验证明了可以直接实现这一目标的直接反射调制激光。我们在混合硅/ III-V平台上演示了该设备，其中硅光子学为滤波器，调制器和反射器提供紧凑的组件，而III-V材料提供增益。原则上，该设备可以在克服其速度限制的同时继承传统直接调制激光器的优势。我们演示了具有低误码率的32/50 Gbaud正交相移键控，并通过实验证明了30 Gbaud 16-QAM的可行性。我们通过实验证明了可以直接实现这一目标的直接反射调制激光。我们在混合硅/ III-V平台上演示了该设备，其中硅光子学为滤波器，调制器和反射器提供紧凑的组件，而III-V材料提供增益。原则上，该设备可以在克服其速度限制的同时继承传统直接调制激光器的优势。我们演示了具有低误码率的32/50 Gbaud正交相移键控，并通过实验证明了30 Gbaud 16-QAM的可行性。该设备可以在克服其速度限制的同时继承传统直接调制激光器的优势。我们演示了具有低误码率的32/50 Gbaud正交相移键控，并通过实验证明了30 Gbaud 16-QAM的可行性。该设备可以在克服其速度限制的同时继承传统直接调制激光器的优势。我们演示了具有低误码率的32/50 Gbaud正交相移键控，并通过实验证明了30 Gbaud 16-QAM的可行性。