Table 2 Parameters of top-layer resonator distributed feedback (DFB) lasers based on nanographenes as active media

Laser device^a	h ^b (μm)	Λ^c (nm)	λ _pump ^d (nm)	λ _DFB ^e (nm)	E _th ^DFB ^f (μJ cm⁻²)	I _th ^DFB ^f (kW cm⁻²)	τ _1/2 ^{DFB g} (MP) (pump pulses)	τ _1/2 ^{DFB h} (EP) (pump pulses)	LSEⁱ (%)
1^A	0.40	307	452	482.5 (TE₀)	90	23
1^B	0.40	311	452	484.4 (TM₀)	50	13
				487.1 (TE₀)	50	13	2 × 10⁴	7.20 × 10²	0.77
1^C	0.40	314	452	488.4 (TM₀)	60	15
				491.0 (TE₀)	95	24
1^D	0.40	316	452	491.3 (TM₀)	100	25
				494.9 (TE₀)	160	40
2^A	0.48	378	545	584.1 (TE₀)	120	27
2^B	0.48	380	545	588.4 (TE₀)	25	6
2^C	0.48	382	545	586.0 (TM₀)	25	6
				590.5 (TE₀)	11	3	> 2.5 × 10⁵	7.5 × 10³	0.62
2^D	0.48	383	545	588.1 (TM₀)	30	7
				592.8 (TE₀)	18	4
2^E	0.48	386	545	593.4 (TM₀)	16	4
				597.5 (TE₀)	15	3
2^F	0.48	388	545	595.1 (TM₀)	16	4
				599.7 (TE₀)	15	3
2^G	0.48	393	545	601.3 (TM₀)	75	17
3^A	0.60	437	610	674.5 (TE₀)	∼6 × 10³	∼1.5 × 10³	> 1.5 × 10⁵
3^B	0.60	446	668	685.7 (TM₀)	∼3 × 10³	∼1 × 10³
			610	689.3 (TE₀)	∼9 × 10³	∼2 × 10³
			668	689.3 (TE₀)	∼4 × 10³	∼1 × 10³	> 2 × 10⁵	> 2 × 10⁵
3^C	0.60	449	668	687.5 (TM₀)	∼6 × 10³	∼1.5 × 10³

^aThe DFB device consists of an active film of polystyrene doped with 1 wt% (error ∼0.1%) of nanographene with a top-layer of dichromated gelatine with an engraved relief grating. The number in the device label refers to the nanographene compound (1, 2, and 3, for FZ1, FZ2, and FZ3, respectively). The letters (A, B, C, and D) refer to devices with different grating periods, thus emitting at different wavelengths
^bFilm thickness (error ∼2%)
^cGrating period (error ∼0.5%)
^dPump wavelength
^eDFB wavelength (error is ± 0.5 nm) for each laser peak (laser mode) observed in the emission spectrum. The waveguide mode (TE₀ or TM₀) to which the laser mode is associated is shown in brackets. The emitted laser light is polarized parallel (for TE₀) or perpendicular (for TM₀) to the DFB grating lines
^fDFB threshold (error ∼10%), determined from Fig. 3a, expressed as energy density, E_th-_DFB, or power density, I_th-_DFB = E_th-_DFB/t_p (t_p is the pump pulse width, values in Table 1)
^gDFB operational lifetime, characterized by the photostability half-life τ_1/2^DFB (determined from Fig. 3d) measured in air under a moderate pump (MP) of E_pump ∼ (4 × E_th-DFB) at 10 Hz (error ∼10%)
^hSame as in g, but under an extreme pump (EP) of E_pump ∼2 × 10⁴μJ cm⁻², at 10 Hz (error ∼10%)
ⁱExperimental laser slope efficiency, obtained from the total emitted light (at any polarization), determined from Supplementary Fig. 4 (error ∼5%)

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