Xin Yin Jochem Verbist Timothy De Keulenaer Bart Moeneclaey Jochen Verbrugghe Xing-Zhi Qiu Johan Bauwelinck 25Gb/s 3-level burst-mode receiver for high serial rate TDM-PONs. 1-3 2015 OFC https://ieeexplore.ieee.org/document/7121777 conf/ofc/2015 db/conf/ofc/ofc2015.html#YinVKMVQB15