A silicon-based four-channel coarse wavelength- division multiplexing (CWDM) (de)multiplexer working in the O-band is proposed and realized. The present on-chip four-channel CWDM (de)multiplexer is composed of four cascaded optical filters with flat-top spectral responses, which are realized by combining a multimode waveguide grating (MWG) and a two-channel mode (de)multiplexer. For the realized flat-top CWDM (de)multiplexer with a ~18-nm channel-spacing, the measured 1-dB bandwidth is as large as 15 nm, which is ~75% of the channel spacing. The thermal sensitivity is also reduced from ~85 pm/°C to 46 pm/°C by introducing the compensation provided by an SU-8 upper-cladding with a negative thermo-optic coefficient.

中文翻译：

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使用级联多模波导光栅的四通道 CWDM（解）复用器


提出并实现了一种工作在O波段的硅基四通道粗波分复用（CWDM）（解）复用器。目前的片上四通道 CWDM（解）复用器由四个具有平顶光谱响应的级联光学滤波器组成，通过组合多模波导光栅（MWG）和两通道模式（解）复用器来实现。对于已实现的通道间距约为 18 nm 的平顶 CWDM（解）复用器，测得的 1 dB 带宽高达 15 nm，约为通道间距的 75%。通过引入具有负热光系数的 SU-8 上包层提供的补偿，热灵敏度也从 ~85 pm/°C 降低至 46 pm/°C。