Fig. 1. Typical four-level system under electrical excitation, threshold behavior, and resonator structures of electrically pumped organic lasers. (a) Four-level system of organic laser medium; (b) output power and FWHM of organic lasers as a function of current density; (c) three typical optical resonator structures

Fig. 2. Structure and performance of the electrically pumped organic laser based on DFB resonator^[11]. (a) Schematic representation of the electrically pumped organic laser based on DFB resonator; (b) lasing spectra at different injected current densities; (c) laser spectra at laser threshold current density; (d) output intensity and FWHM as a function of the driving current; (e) relationship between output power and driving current, where the inset shows a photograph of a device under pulse operation at 50 V

Fig. 3. Electrically driven organic laser based on DFB resonator and its performance^[14]. (a) Cross-section schematic of the electrically driven organic laser; (b) evolution of the emission peak below and above the threshold under different peak current densities; (c) integrated lasing intensity as a function of peak current density; (d) far-field emission images of electrically driven laser below and above the threshold; (e) far-field emission images of the corresponding optically pumped laser

Fig. 4. Electrically pumped organic laser based on DBR resonator and its performance^[23]. (a) Structure schematic of the DBR microcavity electrically pumped organic laser; (b) dependence of output spectral intensity on optical pump intensity; (c) dependence of output spectral intensity on electric pump current density; (d) output emission spectra at different current densities; (e) far field spot patterns at different current densities; (f) dependence of light gain amplification on injected current density under laser diode pump intensity of 0.028 mW/cm² at 405 nm

Fig. 5. Organic exciton-polariton laser and its performance^[29]. (a) Molecular structures of BSFCz and BSTFCz; (b) schematic of DBR cavities; (c) angle-resolved emission spectra of BSFCz DBR cavity exciton polarized exciton lasers, as well as integrated area, FWHM, and energy shift of emission spectra as a function of optical pump fluence; (d) angle-resolved emission spectra of BSTFCz DBR cavity exciton polarized exciton lasers, as well as integrated area, FWHM, and energy shift of emission spectra as a function of pump fluence; (e) far-field spot maps of DBR resonant cavity exciton polarized exciton lasers based on BSFCz and BSTFCz materials at below and above threshold

Fig. 6. Organic laser based on WGM resonator and its performance^[34]. (a) Lasing spectra of a BP2T single-crystal circle microdisk recorded at different pump powers; (b) dependence of emitted intensity of a BP2T single-crystal circle microdisk on the pump energy; (c) lasing spectra and photos from a BP2T single-crystal polygon microdisk