US 12,328,147 B2
System, apparatus and method for optical intensity modulation with direct detection using local oscillator
Christian Malouin, San Jose, CA (US); Jin Hong, Saratoga, CA (US); and Wenhua Lin, Fremont, CA (US)
Assigned to Intel Corporation, Santa Clara, CA (US)
Filed by Intel Corporation, Santa Clara, CA (US)
Filed on Jun. 22, 2021, as Appl. No. 17/353,853.
Prior Publication US 2021/0314068 A1, Oct. 7, 2021
Int. Cl. H04B 10/61 (2013.01); H04B 10/69 (2013.01)
CPC H04B 10/616 (2013.01) [H04B 10/65 (2020.05); H04B 10/69 (2013.01)] 15 Claims
OG exemplary drawing
 
1. An apparatus comprising:
a coherent optical receiver front-end circuit comprising an optical hybrid to receive an O-band optical data signal comprising Pulse Amplitude Modulation (PAM) encoded information and further to receive a local oscillator optical signal, the coherent optical receiver front-end circuit to output an orthogonal electrical signal comprising an in-phase signal and a quadrature phase signal based on the optical signals; and
a processing circuit coupled to the coherent optical receiver front-end circuit to receive the orthogonal electrical signal and to convert the orthogonal electrical signal into sum of squares information lacking any phase information associated with the orthogonal electrical signal; and
a non-coherent receiver comprising a clock and data recovery circuitry to recover the PAM encoded information from the sum of squares information in the absence of any phase information associated with the orthogonal electrical signal.