A continuously tunable low-threshold organic semiconductor distributed feedback laser fabricated by rotating shadow mask evaporation

Continuously tunable solution-processed organic semiconductor DFB lasers pumped by laser diode

“…For the red emitter, a period of Λ = 390 nm was chosen, for the green emitter Λ = 350 nm and for the blue emitting material the grating constant was Λ = 270 nm. The former two grating samples were fabricated with a combination of laser interference lithography and reactive ion etching (RIE) [18]. As substrate material, we used quartz glass plates (GE124) with dimensions of 25 mm x 25 mm.…”

“…Thin films of the active material are either obtained by processing solutions of conjugated polymers [8,9] or evaporating small molecules [10,11] on top of the substrates with surface gratings. Continuous tunability of such solid-state organic DFB lasers has already been demonstrated with several approaches such as holographic dynamic DFB gratings [12], stretchable DFB lasers [13][14][15][16][17], a wedge-shaped film of either the gain material layer [18] or an intermediate high-index layer [19], a continuously changing grating period [20], optofluidic tuning [21], tuning the temperature of the device [22] or DFB lasers that incorporate liquid crystals [23,24]. Furthermore, the general applicability of a wedge-shaped organic DFB laser using evaporated small molecules with a continuous tuning range of up to 25 nm has been demonstrated in spectroscopic and laser-induced fluorescence measurements [25,26].…”

Organic semiconductor distributed feedback (DFB) laser as excitation source in Raman spectroscopy

“…The fabrication details can be found in the work of S. Klinkhammer et al [35]. Due to the correlation between the active layer thickness and the DFB-OSL emission wavelength, a specific organic laser emission wavelength can be obtained by pumping at a spatially defined position on the wedged layer.…”

Electrically Tunable Organic Distributed Feedback Lasers Embedding Nonlinear Optical Molecules

“…In these systems, the integration of electrically tunable lasers would greatly enhance both detection sensitivity, by modulation of the laser intensity or frequency, and capability of parallel optical processing by multi-wavelength excitation. [ 13 ] The emission of organic distributed feedback (DFB) lasers has been previously tuned by mechanical stretching, [ 14 ] by exploiting a "wedge shape" active [ 15 ] or intermediate high index layer, [ 16 ] or by photoisomerizable azo-polymers. [ 17 ] The basic idea of all these approaches is the variation of the DFB period ( Λ ) or of other geometric characteristics and, consequently, of the effective refractive index (n eff ), since the emission wavelength ( λ ) is given by the Bragg condition, m λ = 2 n eff Λ , where m is the diffraction order.…”