Table 5.

Comparison of system sensitivity (both incoherent and laser-based using a variety of detection methods). They are given in approximately chronological order. SC: Supercontinuum light source. FC: Frequency Comb. We have selected a high sensitivity example from each type of system (e.g. CE-DFCS + VIPA detection) to give a general idea for the sensitivity but these numbers will vary some for each system depending on the exact configuration.

Ref	System	Light Source	Absorption Cell	Detection system	${(N\sigma L)}_{\mathit{min}}^{1s}({\text{Hz}}^{-1/2})$	Eff. Path (km)	Resolution (GHz)	Bandwidth/Center λ (nm)/(nm)
[167]	OP-FTIR	Thermal	Open Path	FTS	1.7×10−2	~ 0.4	30	22000/13600
[168]	BB-CRDS	Dye Laser	High-finesse cavity	Grating + CCD	4.1×10−2	30	140	20/660
[169]	LP-DOAS	Xe-arc	Open path	Grating + PDA	1.6×10−2	4.4	620	45/440
[130]	IBB-CES	SC	High-finesse cavity	Grating + CCD	4.3×10−3	19	70	30/670
[170]	CE-DFCS	FC	High-finesse cavity	VIPA	6.0×10−3	14	0.8	25/1600
[171]	CE-DOAS	LED	High-finesse cavity	Grating + PDA	1.6×10−3	13	810	50/460
[172]	CE-DFCS	FC	High-finesse cavity	FTS	7.2×10−4	1.3	0.8	200/3760
[173]	CE-DFCS	FC	High-finesse cavity	Grating + CCD	8.6×10−5	9.2	13.5	4/430
[174]	DCS	FC	Single-pass cell	Dual Comb	9.3×10−4	7.5×10−4	0.1	100/1562
[175]	NICE-OFCS	FC	High-finesse cavity	FTS	2.0×10−3	0.66	2	30/1575
[176]	DCS	FC	Open Path	Dual Comb	3.4×10−2	2	0.1	70/1635