all-optical poling (AOP) ，全光極化

two-photon (TP) microscopy

a vector network analyser (VNA)

conversion efficiency (CE)

Here?CE is defined as?CE?=?P_SH/P_P^2, where?P_SH?and?P_P?are the on-chip?SH and pump power, respectively.

The use of a?high-quality-factor (Q) Si3N4?microresonator not only facilitates the onset of optical poling, but also achieves an ultrahigh?CE on-chip34, benefiting from the doubly resonant enhancement?both at the pump and SH.

使用高質(zhì)量因數(shù) (Q) Si3N4 微諧振器不僅有利于光極化的開始，而且還實(shí)現(xiàn)了超高的片上 CE，這得益于泵和 SH 處的雙諧振增強(qiáng)。

The sample temperature can be varied using a proportional–integral–derivative controller and a Peltier module.

通過矢量網(wǎng)絡(luò)分析儀，EOM，快速PD獲得detuning信號(hào)：

In this scenario, the laser is weakly phase-modulated in an electro-optic modulator (EOM) by a scanning microwave signal from a vector network analyser (VNA). The generated signal at
the SH band is measured by a fast silicon photodetector (PD3) to obtain the VNA response. The transfer function measured by the VNA is explicitly described in Supplementary Note 2, and is found to provide the detuning information of both interacting resonances。

贊

1、細(xì)節(jié)拉滿。對(duì)1-5階模式分布的直接觀測。

2、證據(jù)確鑿。二次諧波（倍頻）能量直接測量。

3、光pump重構(gòu)?？梢栽谌我獠ㄩL產(chǎn)生倍頻

踩

需要一直掃描？不能定波長輸入？

帶寬怎么定義的？

展

確定輸入波長，用熱調(diào)諧掃描，然后熱自鎖穩(wěn)定。