Improvement on tandem-type ultra-high-density multi/demultiplexer performance for use in future super-dense photonic network

我们的目的是减少初级和二级AWG的串扰用于串联型超高密度复用器/解复用器通过光致折射率的变化下，紫外激光通过金属掩模。1.金属掩模制作工艺：我们提出了一种金属掩模制作工艺，采用喷墨打印机绘制掩模图案和复印机将其固定在抗蚀剂片。该方法的优点是一个短的制造过程，约10分钟，成本较低。2.初级AWG的相位误差测量：我们发现，从AWG与光学低相干干涉法获得的干涉图分解时，所采用的光源只覆盖两个窄的光谱区域中的两个连续的峰在其AWG的透射光谱。利用该方法成功地测量了1-THz间距的初级AWG的相位误差分布，其中1.3和1.5 μ mLED的光被组合以覆盖具有两个峰值的光谱。我们制作的金属掩模的AWG的相位误差数据，并成功地减少了7 dB的频谱中的旁瓣。3.二次AWG的相位误差测量：我们已经成功地测量了窄通道间距AWG的相位误差分布，在频域的精度为0.05弧度。这是通过以50 nm/s的激光频率扫描和通过平衡检测方案去除激光强度噪声来实现的。4.超高密度串联多路复用器/解复用器的降低：我们利用上述制造工艺制造了用于次级AWG的金属掩模，并成功地将其中心阵列波导周围的旁瓣串扰降低到-39dB。将它们与相位补偿的初级AWG相结合，1000路复用/解复用器的累积串扰比以前报道的系统降低了5dB。

Our aim was to reduce the crosstalk of primary and seconday AWGs used in a tandem-type ultra-high density multi/demultiplexer by means of photoinduced refractive index change under UV laser light through metal masks.1.Metal mask fabrication process : We proposed a metal mask fabrication process employing an inkjet printer to draw the mask pattern and a copy machine to fix it on a resist sheet. The advantage of the method is a short fabrication process for around 10 minutes and a lower cost.2.Phase error measurement of primary AWG : We found that an interferogram obtained from an AWG with optical low coherence interferometry is decomposed when the employed light source covers only two narrow spectral regions at two successive peaks in its AWG transmission spectrum. This was utilized successfully for measuring the phase error distribution of a 1-THz-spaced primary AWG, where the lights from 1.3 and 1.5 μm LEDs were combined to cover the spectrum with two peaks. We fabricate the metal mask for the AWG from the phase error data and succeeded in reducing the sidelobe in the spectrum by 7 dB.3.Phase error measurement of secondary AWGs : We have succeeded in measuring the phase error distributions of narrow-channel spacing AWGs with an accuracy of 0.05 rad in the frequency domain. This was achieved by sweeping the laser frequency at 50nm/s and by removing the laser intensity noise with a balanced detection scheme.4.Reduction of an ultra-high density tandem multi/demultiplexer : We fabricated metal masks for the secondary AWGs with the above fabrication process and succeeded in reducing the sidelobe crosstalk to -39 dB around their central arrayed waveguides. By combing them with the phase-compensated primary AWG, the accumulated crosstalk of the 1000-channel multi/demultiplexer was reduced by 5 dB as compared with the system previously reported.