Qalabku waa modul silikoon avalanche photodiode oo leh afar unug oo isku mid ah, oo leh qalab horudhac ah oo ku dhex jira, kaas oo kor u qaadi kara signalka daciifka ah ee hadda jira oo u rogi kara wax soo saarka signalka korantada, isagoo ogaanaya habka beddelka "optical-electrical-signal amplification".