Introduction - Database for Excitation Emission Spectra in Combustion Research
Laser induced fluorescence (LIF) is a well-known technique to detect different species in combustion processes. It is highly selective, sensitive and nonintrusive. Pulsed-laser planar imaging allows resolution in species, space and time. The detailed understanding of gas-dynamic processes is important for engineering design to increase efficiency and minimize pollutants from combustion devices. With laser optical measurements (like LIF) it is possible to detect molecules and radicals inside the flame. The resultls provide information about combustion kinetics, flame front, reaction zone, formation of pollutants, formation of soot etc.
The aims of the excitation emisssion spectra (EES) database are:
To give an overview of laser-induced fluorescence (LIF) in flame spectroscopy for scientist and students in a wide range of the laser excitation wavlength: In the VIS range from 670 nm to 419 nm and in the UV range from 321 nm to 210 nm. Now it is very easy to get information about the laser excitation of combustion speceis like NO, CO, OH, CH, C2, CN and O2. The EES database also provides information of the interaction of the emission signals of different species.
To find appropriate electronic transitions to excite combustion species like NO, CO, OH, CH, C2, CN or O2 for selective laser-induced fluorescence measurements.
To find appropriate electronic transitions where the emission signals of different species can be seperated.
In the EES database you will find information of laser excitation and emissions of the following molecules and radicals:
| Species: |
Transitions |
Excitation wavelength range [nm] |
Emissions [nm] |
| NO | g-bands: A2S+ - X2P (0,4), (1,5) bands | 272,5 to 259,7 nm | 272 nm, 260 nm, 248 nm, 237 nm, 227 nm, 215 nm |
| NO | g-bands: A2S+ - X2P (0,3), (1,4) bands | 259,7 to 248,0 nm | 286 nm, 272 nm, 260 nm, 248 nm, 237 nm, 227 nm, 215 nm |
| NO | g-bands: A2S+ - X2P (0,2), (1,3) bands | 248,0 to 237,2 nm | 286 nm, 272 nm, 260 nm, 248 nm, 237 nm, 227 nm, 215 nm |
| NO | g-bands: A2S+ - X2P (0,1), (2,3) bands | 237,2 to 227,1 nm | 301 nm, 286 nm, 272 nm, 260 nm, 248 nm, 237 nm, 227 nm, 215 nm, 205 nm |
| NO | g-bands: A2S+ - X2P (0,0), (1,1), (2,2) bands | 227,1 to 215,6 nm | 355 nm, 335 nm, 317 nm, 301 nm, 286 nm, 272 nm, 260 nm, 248 nm, 237 nm, 227 nm, 215 nm, 205 nm, 196 nm |
| NO | g-bands: A2S+ - X2P (1,0), (2,1), (3,2) bands | 215,6 to 210,0 nm | 327 nm, 311 nm, 295 nm, 281 nm, 268 nm, 256 nm, 245 nm, (234 nm), 224,5 nm, 215 nm, 205 nm, 196 nm |
| CO | B1S+ - X1S+ (0,0), (1,1) bands | 230,5 to 229,5 nm | |
| CO | C1S+ - X1S+ (0,0) band | 217,7 to 217,4 nm | |
| OH | A2S+ - X2P (0,0), (1,1) bands | 321,0 to 302,0 nm | 278 - 300 nm, 302 - 330 nm, 342 - 355 nm |
| OH | A2S+ - X2P (1,0), (2,1) bands | 302,0 to 278,5 nm | 261 - 270 nm, 278 - 300 nm, 302 - 333 nm, 342 - 359 nm |
| OH | A2S+ - X2P (2,0) band | 278,5 to 259,0 nm | 259 - 275 nm, 278 - 302 nm, 302 - 335 nm, 342 - 359 nm |
| OH | A2S+ - X2P (3,0), (4,1) bands | 259,0 to 243,0 nm | 265 - 275 nm, 281 - 303 nm, 305 - 330 nm |
| CH | A2D - X2P (0,0) band | 440,5 to 420,0 nm | |
| CH | B-X (2,1) band | ||
| CN | B2S+ - X2S+ (0,2), (1,3) bands | 460,6 to 447,0 nm | 389 nm, 421 nm |
| CN | B2S+ - X2S+ (0,1), (1,2) bands | 421,6 to 419,8 nm | 359 nm, 388 nm, 421 nm |
| O2 | Schumann-Runge bands: B3Su- - X3Sg- | ||
| C2 | Swan bands: d 3Pg <--> a 3Pu (0,3), (1,4), (2,5) bands | 690 to 620 nm | 438 nm, 473 nm, 516 nm, 563 nm, 619 nm, 685 nm |
| C2 | Swan bands: d 3Pg <--> a 3Pu (0,2), (1,3), (2,4) bands | 620 to 563 nm | 438 nm, 473 nm, 516 nm, 563 nm, 619 nm, 685 nm |
| C2 | Swan bands: d 3Pg <--> a 3Pu (0,1), (1,2), (2,3), (3,4) bands | 563 to 518 nm | 438 nm, 473 nm, 516 nm, 563 nm, 619 nm, 685 nm |
| C2 | Swan bands: d 3Pg <--> a 3Pu (0,0), (1,1), (2,2), (3,3) bands | 518 to 474 nm | 438 nm, 473 nm, 516 nm, 563 nm, 619 nm, 685 nm |
| C2 | Swan bands: d 3Pg <--> a 3Pu (1,0), (2,1), (3,2), (4,3) bands | 474 to 438 nm | 438 nm, 473 nm, 516 nm, 563 nm, 619 nm, 685 nm |
| C2 | Swan bands: d 3Pg <--> a 3Pu (2,0), (3,1), (4,2) bands | 438 to 409 nm | 438 nm, 473 nm, 516 nm, 563 nm, 619 nm, 685 nm |
| C2 | Swan bands: d 3Pg <--> a 3Pu emissions | UV | 438 nm, 473 nm, 516 nm, 563 nm, 619 nm, 685 nm |
| C2 | Deslandres-d'Azambuja bands: C 1Pg <--> A 1Pu (0,3), (1,4) bands | 470 to 440 nm | 339 nm, 360 nm, 385 nm, 410 nm, 438 nm |
| C2 | Deslandres-d'Azambuja bands: C 1Pg <--> A 1Pu (0,2), (1,3) bands | 438 to 420 nm | 339 nm, 360 nm, 385 nm, 410 nm, 438 nm |
| C2 | Deslandres-d'Azambuja bands: C 1Pg --> A 1Pu emissions | 690 to 209 nm | 339 nm, 360 nm, 385 nm, 410 nm, 438 nm |
| C2 | Mullikan bands: D 1Su+ <--> X 1Sg+ (0,2), (1,3), (2,4) bands | 253 to 248 nm | 231 nm |
| C2 | Mullikan bands: D 1Su+ < --> X 1Sg+ (0,1), (1,2), (2,3) bands | 242 to 238 nm | 231 nm, 360 nm, 385 nm, 410 nm, 438 nm, 473nm |
| C2 | Mullikan bands: D 1Su+ < --> X 1Sg+ (0,0), (1,1), (2,2) bands | 233 to 229 nm | 231 nm, 360 nm, 385 nm, 410 nm, 438 nm, 473nm |
| C2 | Mullikan bands: D 1Su+ < --> X 1Sg+ (1,0), (2,1), (3,2) bands | 225 to 218 nm | 231nm |
| C2 | Mullikan bands: D 1Su+ < --> X 1Sg+ (2,0), (3,1), (4,2) bands | 217 to 212 nm | 231nm |
| C2 | Freymark bands: E 1Sg+ < --> A 1Pu (0,3), (1,4), (2,5) bands | 239 to 232 nm | 201 nm, 207 nm, 214 nm, 222 nm, 229 nm, 238 nm |
| C2 | Freymark bands: E 1Sg+ < --> A 1Pu (0,2), (1,3), (2,4) bands | 230 to 224 nm | 201 nm, 207 nm, 214 nm, 222 nm, 229 nm, 238 nm |
| C2 | Freymark bands: E 1Sg+ < --> A 1Pu (0,1), (1,2), (2,3) bands | 222 to 216 nm | 201 nm, 207 nm, 214 nm, 222 nm, 229 nm, 238 nm |
| C2 | Freymark bands: E 1Sg+ < --> A 1Pu (0,0), (1,1), (2,2) bands | 214 to 210 nm | 201 nm, 207 nm, 214 nm, 222 nm, 229 nm, 238 nm |