fēixiànxìngguāngxué
ㄈㄟ ㄒㄧㄢˋ ㄒㄧㄥˋ ㄍㄨㄤ ㄒㄩㄝˊ
Simplified 非线性光学
Taivo → Settings → Partner inbox → Make the link. It stays in this browser.
Keep 非線性光學 and it comes back until you know it.