Table 3.

Peak CE and 1 dB bandwidth comparison of different grating coupler designs demonstrated on various SiN platforms in S-C-L bands.

SiN Coupler	Max. CE (dB)	Bandwidth-δλ1dB (nm)	λmax (nm)	tSiN (nm)	Clad	Etch step(s)	Bottom mirror	Platform
Ref. 25	−1.3	80	1536	400	SiO2	2	N	Non-Uniform, SiN/SOI
Ref. 26	−2.5	65	1564	600	air	1	N
Ref. 27	−2.5	53	1484	400	SiO2	1	Y	Uniform, SiN
Ref. 34	−3.7	54	1555	700	air	1	N
Ref. 35	−4.2	67	1570	400	SiO2	1	N
Ref. 29	−2.29	49	1573	500	air	1	Y
Ref. 29	−2.58	52	1576	400	SiO2	1	Y
Ref. 23	−1.5	60 (3 dB)	1555	600	air	2	N	Non-Uniform, SiN
Ref. 28	−1.75	76.34 (3 dB)	1550	325	SiO2	1	N
Ref. 24	−2.56	46.9	1550	220	SiO2	2	N
This work	−1.17	40	1571	500	air	1	Y
This work	−1.24	39	1572	400	SiO2	1	Y