We report InP/InGaAs modified unitraveling-copyright balanced photodiodes (PDs). The back-illuminated PDs were flip-chip bonded on diamond submounts for enhanced heat sinking. The device demonstrated a 3-dB bandwidth of 8 GHz and a 30-dB common-mode rejection ratio at frequencies of <; 10 GHz. https://www.chiggate.com/3m-speedglas-9002nc-welding-helmet-fashion/