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To improve the detection and recognition performance of DAS in complicated multi-source interfering environments, a blind multi-source separation method is proposed based on the FastICA, which utilizes the independency and non-Gaussianity of different sources.

Cardiac troponin I (cTnI) is one of the most sensitive and specific markers of myocardial cell injury, which can detect even minor myocardial damages. It is recognized as the main biochemical marker of the rapid diagnosis of acute myocardial infarction (AMI) and acute coronary syndrome (ACS). In this study, a label-free biosensor that utilizes the birefringence property of a nematic liquid crystal (LC) for the detection of cTnI is demonstrated. A chemically sensitive film with specific molecular recognition ability was decorated on the surface of a substrate, and the LC molecules were arranged in a vertically oriented order under the influence of the sensitive film, and a dark background signal was obtained using a polarizing optical microscope. When the antigen-antibody specifically binds to form a stronger acting force, the orientation of the LC molecules changes, resulting in a bright optical appearance. This LC-based immunosensor not only has the advantages of a facile structure, low cost and excellent specificity but also high sensitivity (a low detection limit of 1 pg ml-1), and has a promising future in biomedical related fields.

In this paper, we proposed and fabricated a liquid crystal (LC) lens with spatially separated focuses via liquid crystal photoalignment technology. The novel lens is an integration of the polarisat...

Two-dimensional liquid crystal polarisation grating based on twist liquid crystal has been demonstrated and fabricated by polarisation holography in this paper. The maximal diffraction efficiency of the second order is up to 90%. And the two-dimensional liquid crystal polarisation grating has the properties of electrically tenability and polarisation tenability. The two-dimensional polarisation grating diffracts light into a spot array. Different direction diffraction light is with different polarisation states. The intensity of the different orders diffraction light is optically controlled.

Highly effective surface-enhanced Raman substrates with shape-diversified silver nanostructures on Al foil (AlF) were fabricated by galvanic replacement reaction in micellar template which is easy to control, simple and cost-effective. Due to the localized surface plasmon resonance (LSPR) of silver nanostructures, the substrates were used as surface enhanced Raman substrates. The shape-diversified silver nanostructures on AlF exhibited stronger surface enhanced Raman scattering (SERS) effects compared with flowerlike Ag nanostructures on ITO glass substrate fabricated by electrodeposition in micellar template. The maximum Raman enhancement factor of 109 fold was obtained, which is 236 times larger than the flowerlike silver nanostructures on ITO glass substrate. The scanning electron microscope (SEM) images show that the size and shape of the nanostructures and surface morphology make a valuable contribution to SERS. Raman enhancement experiments of three Raman probes were studied, which shows that different vibrational modes of Raman probe affect SERS effect. The fabricated shape-diversified silver nanostructures on AlF fabricated by galvanic replacement reaction in micellar template are cheap, controllable and simple. It could be potentially useful in SERS field such as imaging applications and highly sensitive molecule detecting.

Flowerlike silver nanostructure substrates were fabricated in liquid crystalline phase and the distance dependent property of metal enhanced fluorescence for such substrate was studied for the first time. The distance between silver nanostructures and fluorophore was controlled by the well-established layer-by-layer (LbL) technique constructing alternate layers of poly (allylamine hydrochloride) (PAH) and poly (sodium 4-styrenesulfonate) (PSS). The Rhodamine 6G (R6G) molecules were electrostatically attached to the outmost negative charged PSS layer. The fluorescence enhancement factor of flowerlike nanostructure substrate increased firstly and then decreased with the distance increasing. The best enhanced fluorescence intensity of 71 fold was obtained at a distance of 5.2 nm from the surface of flowerlike silver nanostructure. The distance for best enhancement effect is an instructive parameter for the applications of such substrates and could be used in the practical MEF applications with the flowerlike nanostructure substrates fabricated in such way which is simple, controllable and cost-effective.

Thermal annealing effect on an organic distributed feedback (DFB) laser excited from a semiconducting polymer gain layer, poly(2-methoxy-5-(2’-ethyl-hexyloxy)-p-phenyl-envinylene) (MEH-PPV), is reported. The morphology, absorption and photoluminescence (PL) spectral characteristics of the MEH-PPV film annealed at different temperatures were analyzed. The amplified spontaneous emission (ASE), the optical gain and loss coefficients were also investigated. The organic lasing behaviors including threshold, energy conversion efficiency and polarization state in a DFB laser device were studied. The results show that the optical properties of the organic semiconducting laser can be enhanced by thermal annealing effect. The single mode laser emission at 622.4 nm with lower lasing threshold 0.2 μJ/pulse and higher energy conversion efficiency 6.71% was achieved with thermal annealing at 120 °C. The thermal annealing treatment decreases laser threshold and increases laser energy conversion efficiency dramatically, which shows the potential in ultra-low cost organic semiconducting polymer DFB lasers.

Rational design of liquid crystals (LCs) with excellent phase state and rotational viscosity has been a crucial technique for response speed improvement of LC wavefront corrector. A complete process for theoretically evaluating the phase state and rotational viscosity of fast response LCs using a fully atomistic molecular dynamics is reported. Predicted trends in molecular order, phase-transition temperature between metastable states and rotational viscosity show excellent agreement with experimental results. We also demonstrate that overestimation of the attraction both between and within molecules in the general Amber force field mainly leads to a systematic shift in the phase-transition temperature, rotational viscosity and figure-of-merit for fast response LCs. With further optimisations of intermolecular potential, simulation procedure and data processing, this fully atomistic simulation will be a useful evaluation method of response performance of LC materials.

An experimental analysis was conducted to investigate the fitting error of diffractive liquid crystal wavefront correctors (LCWFCs). First, an experiment was performed to validate the theoretical equations presented in our previous work Cao et al., 2009 [9] . The results showed an apparent discrepancy between the theoretical and measured results for the fitting error. This difference was examined and the influence of nonlinearities and rounding errors generated by the LCWFC was analyzed and discussed. Finally, the fitting error formula of the LCWFC was modified to obtain a more effective tool for the design of LCWFCs for atmospheric turbulence correction. These results will be useful for researchers who design liquid crystal adaptive optics systems for large-aperture ground-based telescopes.

This letter reports the optical pumped lasing behaviours of a three-layer Bragg resonance cavity consisting of dye-doped cholesteric liquid crystal (DDCLC) microdroplet, polyglycerol-2 and hollow glass microsphere. The function of PG2 is to control the parallel anchoring of the liquid crystal (LC) molecules on the surface of the LC microdroplet. The whispering-gallery mode (WGM), radial Bragg (photonic bandgap, PBG) mode and Bragg WGM (BWGM) are observed in DDCLC microspheres with different helical pitches and LC refractive indices. The formation mechanisms of six types of lasing emission conditions are analysed in detail. The study results present the prospect of controlling the output mode of the laser. Furthermore, such solid shell-based DDCLC microspheres have outstanding potential applications in miniaturised 3D Bragg lasers, sensors, and integrated and tunable optical devices.

Control experiments were performed to improve the slope conversion efficiency of the organic distributed feedback laser by varying the dissolution solvents of the laser gain layer, a conjugated polymer poly(2-methoxy-5-(2ʹ-ethyl-hexyloxy)-1,4-phenylene-vinylene) (MEH-PPV) in this work. The distributed feedback configuration of the laser was prepared by holographic photopolymerisation of the polymer/liquid crystal (HPDLC) mixture. Experimental results showed that the tetrahydrofuran (THF) solvent cast laser gain layer had a lower lasing threshold (0.28 μJ/pulse) and a higher slope conversion efficiency (7.8%) than that of the xylene solvent cast laser gain layer (0.5 μJ/pulse, 4.9%). Thin film waveguide characterisation demonstrated that the THF-cast film possessed a smaller waveguide loss (5.3 cm−1) and larger net gain (17.1 cm−1) than the xylene-cast film (8.3 cm−1, 15.7 cm−1). Absorbance and photoluminescence spectra indicated that the THF-cast film showed brighter luminescence at 620 nm and lar...

A series of 4ʹ-(4-alkyl-phenyl)-2ʹ,6ʹ-difluorotolane isothiocyanate liquid crystal (LC) compounds were synthesised, and their phase transitions and electrooptical properties were investigated. These compounds exhibit high birefringence, about 0.47–0.52. As the number of carbon atoms in the alkyl chains increases, these LC compounds can exhibit smectic phases. When these LCs were mixed into the commercial LCs, the birefringence values of LC mixtures become higher than pure commercial LCs, and the visco-elastic coefficients of five LC mixtures are very close to each other at every test temperature. The results of response properties indicate that the compounds with a tri-fluorine substitution and n-propyl end group possess better response performance than the others. These LC compounds are particularly attractive for achieving fast response times in LC optic devices.

Ferroelectric liquid crystal (FLC) with I-N*-C* phase sequence is most attractive due to its continuous grey level and fast response; however, the alignment problem of two-domains defect restricted its application. In this work, one kind of one terminal polymerizable nematic liquid crystal (NLC) mesogen was mixed to FLC to improve its alignment quality. Experimental results showed that mono-domain uniform alignment of FLC can be obtained with mixing NLC polymer. With optimized concentration, the FLC devices could offer half-V-shaped electric-optical characteristic of driving contrast of 182:1 and fast response of 300 µs even after polymerization. This work can provide one simple and effective method for fabricating stable I-N*-C* FLC devices.

Correction for ‘A liquid-crystal-based immunosensor for the detection of cardiac troponin I’ by Chunli Xia et al., Analyst, 2020, 145, 4569–4575, DOI: 10.1039/D0AN00425A.

In this Letter, a dye-doped cholesteric liquid crystal (DDCLC)-filled hollow glass microsphere is demonstrated to be a resonator with good temperature response. A diglycerol layer is used to wrap the DDCLCs microdroplet to keep it steady and control its orientation. The whispering gallery mode (WGM) lasing and photonic band gap (PBG) lasing caused by two different mechanisms were obtained under the pump of a pulsed laser, and the temperature response of these two kinds of lasing was studied. For the liquid crystal and chiral material used in this Letter, both the WGM lasing and the PBG lasing have a blue shift in wavelength with increasing temperature.

To process real-time wavefront signal in our liquid crystal adaptive optics system (LCAOS), a real-time wavefront processor (RTWP) with graphics processing unit (GPU) accelerator is developed. A series of parallel acceleration algorithm is implemented to reconstruct wavefront, compute gray map and process lookup table (LUT). Especially, an algorithm by using symmetry of Zernike polynomial is designed to compute gray map and it provides a speedup of 3.16. Finally, the total computing time in our RTWP is 109 μs and temporal bandwidth in our LCAOS is 45 Hz; it is shown that our RTWP has the ability to real time process wavefront signal in our LCAOS.

In this Letter, a method of stacking two opposite-handed cholesteric liquid crystals (CLCs) with the same pitches and the same surface azimuthal angles to generate vector beams from homogeneous linear polarization is proposed. By this means, vector beams with arbitrary orders can be generated based on point-to-point photo-alignment technology. In our experiment, radially polarized, azimuthally polarized, and high-order vector beams with high efficiency have been generated. The device operates light polarization within the Bragg reflection polychromatic bandgap. Our proposal also provides the possibility to generate reflective hybrid-order Poincare beams if these two CLC layers are impressed with different topological charges. It has great potential for reflective photonics applications in high-resolution imaging, focusing, and information processing.

To address the accommodation-convergence conflict problem in conventional augmented reality (AR) head-mounted displays, we propose a compact multi-plane display design based on cholesteric liquid crystal (CLC) reflective films and a polarization switch. Because of the polarization selectivity of CLC films, circularly-polarized light with different handedness is reflected by different CLC films, resulting in different optical path lengths and different image depths by the lens. A flicker-free dual-plane prototype with correct focus cues and relatively low operating voltage has been implemented. Moreover, a multi-plane AR display scheme with more than 2 depth planes is proposed by stacking multiple CLC films and polarization switches together.

Theoretical and experimental analysis of the rewriting time of liquid crystal (LC) optical rewritable (ORW) e-paper was conducted. The equations of rewriting time of alignment molecule SD1 film with and without interaction with LC based on diffusion model were derived, which shows that the rewriting time of LC ORW e-paper could be shortened by enlarging light intensity or decreasing azimuthal anchoring energy. The rewriting time of pure SD1 films and LC ORW cells was measured under different light intensities. And LC ORW cells with different azimuthal anchoring energy were prepared for rewriting time measurement. A good agreement between experimental and theoretical results was obtained, which indicates that using larger light intensity and making LC cell with smaller azimuthal anchoring energy, ORW rewriting time could be decreased to the amount suitable for practical use.

Base on the Lorentz-Lorenz formula, magnetic response in metamaterial composed of randomly dispersive SiC microspheres is demonstrated theoretically around 13 m mid-infrared wavelength. By adjusting the microspheres volume filling fraction the permeabilities both less than one and more than one can be obtained. Through parameters optimization, isotropic negative permeability is represented. Electromagnetic simulation shows the mechanism for magnetic effects and negative permeability in SiC microspheres. 2013 Elsevier Ltd.

Self-aligned liquid crystals containing randomly dispersed nanoparticles are proposed to realise hyperbolic metamaterials at visible spectrum. Opposite signs for anisotropic permittivity tensors originated from the scattering of metallic nanoparticles in liquid crystals are achieved. Tunable effective wavelength properties are also demonstrated by choosing dielectric-metal core-shell nanoparticles.

The optimal cell gap of nematic liquid–crystal wavefront corrector (LCWFC) is proved theoretically by numerical computation of the Ericksen–Leslie equation based on finite differences and confirmed experimentally. The numerical results of optimizing cell gap overcome the constraints of many approximations e.g. the small angle approximation and agree much better with the experimental data than those of analytical solution. Therefore, this method supplies a useful tool to achieve the optimal cell gap of a nematic LCWFC with high precision. Together with high birefringence and low rotational viscosity liquid crystal (LC) material effect, a nematic LCWFC with response time of sub-millisecond can be achieved in the visible spectral region.

Large-scale uniform β-CoOOH nanospheres were prepared under ultrasonic conditions through coordination self-assembly of heterogenite nanosheets. The nanospheres were composed of about 10 nm-thick single-crystalline nanosheets with the averaged diameter of about 120 nm. A rational mechanism based on the coordination self-assembly and oriented attachment through ultrasonic assisted process is proposed for the self-assembly of heterogenite single-crystal nanosheets into nanospheres. This result may facilitate not only the exploration of the preparation of the heterogenite nanostructures through a simple and facile controlled-route, but also a general approach for the large-scale, high-purity growth of different nanostructures of a wide range of transition metal correlated materials.

Ultrafast switchable wide angle negative refraction in a novel dual-frequency liquid crystal mixture is demonstrated experimentally. Laterally fluorinated isothiocyanato phenyl-tolane liquid crystal compound is doped into Merck MLC-2048 to acquire the high birefringence dual-frequency liquid crystal. The maximum negative refraction angle achieved is about 12° and the switching time is only 25 ms for a 40-μm cell which is two orders faster than switchable negative refraction achieved before in nematic liquid crystals. Such properties provide a feasible approach to design negative refraction devices based on liquid crystals.

Reverse hexagonal lyotropic liquid crystal template is proposed to achieve optical hyperbolic metamaterial composed of silver nanowire arrays. All angle negative refraction is obtained during the wide wavelength range from near-infrared to visible light. Hyperbolic metamaterial incorporated with gain dye molecules is calculated to show the possibility of eliminating energy losses and the transmittance can be enhanced in the selected wavelength range. 2013 Published by Elsevier B.V.

Digital overdriving technique is used to enhance response performance of liquid crystal device for wave front correction, combined with electro-optic effect. Generally, using phase wrapping technique, liquid crystal wave front correction only needs 1 phase retardation. In this new driving scheme, it was increased to 1.2 and only the phase retardation from 0 to 1 was used for real correction. Different from conventional method, transition grey level is needed for each grey level as to accelerate its response. This method could enhance the response time up to 50% and unify all the grey-to-grey responses to one equal value. It can be easily implemented into every conventional Liquid Crystal devices without any additional hardware modification. A liquid crystal on silicon device with synthesised liquid crystal material by our lab was used to demonstrate its feasibility. After optimisation, the response time was reduced from nearly 3.3ms down to 1.55ms.

Negative refraction (NR) is a promising technique that provides an opportunity to manipulate beam behaviour. We have demonstrated experimentally the controllable NR with large refraction angle at visible wavelength in the novel high birefringence (Δn) liquid crystals. When the Δn of liquid crystal reaches 0.42, the NR angle and critical incident angle reach –14° and 23.2°, respectively, which are much larger than those achieved before by other liquid crystals. By applying the electric field, we control the switch from NR to positive.

In this study, three kinds of low-viscosity difluorooxymethylene-bridged (CF2O) liquid crystals (LCs) were synthesised. These materials exhibit low melting point and low viscosity at room temperature. The viscosity of the final LC mixture significantly decreased when LC compounds were mixed with high-birefringence (Δn) isothiocyanato LCs. The tested curves with varied temperatures of LC mixtures showed that some CF2O LC compounds could enhance the response performance of high-Δn LCs in a specific temperature range. Therefore, LC compounds with low viscosity could become a component of LC mixtures with fast response performance.

A novel liquid crystal wave front corrector (LCWFC) based open loop adaptive optics testbed for nonpolarized light was introduced in this paper. A polarizing beam splitter (PBS) was used behind the LCWFC to divide the reflected nonpolarized light into two orthogonal polarized lights with and without the modulation effect for high resolution imaging and aberration detection respectively. The alignment direction of LC molecules was parallel to the polarization direction of the light PBS reflected. This configuration was simple and easy for construction. It avoided the energy loss due to the use of polarizer for conventional LCWFC based closed loop adaptive optics system. Furthermore, it could be switched into closed loop configuration very easily, which was useful for quantitative system performance evaluation. The detailed construction and operation was reported in Section 2. In Section 3, this testbed was deployed at the coude focus of the 2.16 m telescope at the Xinglong Station of the Beijing Astronomical Observatory. The observation of star Arcturus was done. The Full Width Half Maximum (FWHM) resolution was improved from 2.12″ to 0.64″ successfully.

In this paper, a liquid crystal device for generating transflected optical vortices with high efficiency based on Pancharatnam-Berry phase is devised and demonstrated experimentally. In the experiment, both photo-alignment material and polymer-alignment material are used for assembling three-dimensional distributed liquid crystal polymer and cholesteric liquid crystal. Through the interaction between the incident light and the device, both transmitted light and reflected light get spin-orbital angular momentum conversion. Moreover, the amount of transmitted and reflected beams can be modulated by the input polarization. In our proposal, the device is dual functional, low-cost and simple in manufacturing process.

This paper reports 65° beam steering using a slanted holographic polymer dispersed liquid crystal (HPDLC) grating with the slanted angle at 16.6°. The HPDLC grating was fabricated using a convenient one-step holographic technique. The SEM image confirmed the slanted grating configuration. The grating showed anisotropic diffraction characterizations. The diffraction efficiency for the p-polarized light was as high as 80%. The Bragg angle deviation diffraction and the transmittance properties of the slanted HPDLC grating were investigated. The slanted HPDLC grating can be switched with an external electric field. The results in this work provide an optional method to fabricate a slanted grating configuration. The slanted HPDLC grating can be used in the field where polarized beam steering is required.

In this paper, a new type of hydrogen‐bonding‐directed layer‐by‐layer (LBL) ultrathin film with photosensitive cinnamoyl chromophores was prepared. It could induce uniform alignment of liquid crystals (LCs) after being irradiated by linearly polarised ultraviolet light (LPUVL). The hydrogen‐bonding‐directed formation of a photochromic multilayer film was achieved on the basis of an alternating assembly of poly(4‐vinylpyridine) (PVPy) and poly(4‐acryloyloxy)cinnamic acid (PCA). The assembly process was followed by UV–visible spectroscopy. The nature of the interaction between the two polymers was identified as a hydrogen bond through Fourier transform infrared spectroscopy. When the film was irradiated by LPUVL, the cinnamoyl units in the film underwent [2+2] cycloaddition along the electric vector direction of the LPUVL. The polarised UV–visible spectra proved that the film was anisotropic, and then the film could induce homogeneous alignment of nematic LCs. With the number increment of the bilayers, the ...

A novel layer‐by‐layer (LBL) film containing dual photoreaction groups, cinnamoyl and azobenzene, was prepared from poly(diallyldimethylammonium chloride) (PDDA) and a photosensitive polyanion, PCAzo, in aqueous solution via electrostatic attraction. The film was able to induce uniform alignment of liquid crystals (LCs) with good stability and 2.3° pretilt angle by oblique irradiation with linearly polarised ultraviolet light (LPUVL). UV absorption and FTIR spectroscopic results indicate that the photoreactions of the two photoreactive groups jointly participate in generating the anisotropy of the film. The dichroic ratio of the film was found to depend on the number of adsorbed layers. The thicker film has the larger dichroic ratio after the LPUVL irradiation. The reorientation behaviour of the LC molecules was found to be associated with the LBL film thickness. Experiment results revealed that the photo‐crosslinking of the cinnamoyl groups was responsible for the stability of the anisotropic orientation...

A novel strategy based on self‐assembly technology was devised for design of photosensitive material as a ferroelectric liquid crystal (FLC) alignment layer. This development offers new tools for the study and control at the molecular level of the interaction of FLCs with solid surfaces. The photoreactive material was self‐assembled to the substrate by covalent bond linkage due to a special chemical adsorption reaction. Through ester bond linkage, a cyano group with strong polarity was introduced to be terminus of the film. Under irradiation of linearly polarised ultraviolet light, an optically anisotropic self‐assembled film was easily obtained. The irradiated film was demonstrated to result in homogenous alignment of FLC by optical transmittance measurements and polarising optical microscopy images of a FLC cell at different rotation angles. The alignment quality of the FLC on this self‐assembled monolayer film is comparable to that of commercial rubbed polyimide film. Furthermore, it was also found tha...

A novel vertical alignment film for nematic liquid crystals is reported based on electrostatic self‐assembly of alkyl sulfonic salts in aqueous solution. A series of self‐assembled films with different alkyl chain lengths were prepared and used as alignment films. It was revealed that only when the number of carbon atoms in the alkyl chain approaches 11 or larger, could the self‐assembled film induce vertical alignment of liquid crystals. We also found that the homeotropic alignment of liquid crystals was related to the surface roughness of self‐assembled films. In addition, this vertical alignment film showed good electro‐optical characteristics and excellent thermal stability.

Photosensitive fluorinated polyesters (polymer‐n) of varying molecular mass M n (number‐average molecular mass) were synthesized. The thin films formed from polymer‐n samples could induce liquid crystal (LC) alignment after irradiation by linearly polarized ultraviolet light. The LC alignment direction on the irradiated films was investigated in detail by linearly polarized infrared spectroscopy and polarizing optical microscopy. It was found that LC alignment behaviour changed with change in the molecular mass of polymer‐n: irradiated films with lower or higher M n induced homeotropic or homogenous alignment, respectively. There was no clear morphological anisotropy in these aligned films, as observed by atomic force microscopy. The surface energies of the irradiated films were also measured using the indirect contact angle method, where both surface energy and its polar component increased with increasing M n. The variation in M n could be considered as a main reason for varying alignment behaviour.

In this paper, a new layer-by-layer (LBL) ultrathin film with photosensitive cinnamoyl chromophores was prepared. It could induce uniform alignment of liquid crystals (LC) after irradiated by linearly polarized ultraviolet (LPUV) light. First, a photosensitive polycation containing cinnamoyl side groups was synthesized. Then a layer-by-layer ultrathin film was prepared in an aqueous solution of the polycations and poly (sodium 4-styrenesulphonate). The spectra of UV–vis absorption and ellipsometric measurement showed that the LBL film was uniform and suitable for the photoalignment of LC. When the film was irradiated by LPUV light, the cinnamoyl units in the film underwent [2 + 2] cycloaddition along the electric vector direction of the LPUV light. The polarized UV–vis spectra also proved that the film was anisotropic, and then the film could induce the homogeneous alignment of nematic LC. With the number of bilayers increasing, the alignment effect of multilayer film became better, and the contrast ratio became higher.

A photoalignment film derived from photosensitive self-assembled monolayer with a p-phenylenediacrylate group is reported. The precursor film was prepared by self-assembled reaction of chemical adsorption, and then the film was irradiated by linearly polarized ultraviolet light. The photoalignment film induces nematic liquid crystal to align homogeneously, and the alignment direction of the liquid crystal molecules is perpendicular to the polarized direction of incident ultraviolet light. By variation of the length of the alkane chain and the different functional group at its terminus, the self-assembled photoalignment films with different polarity were prepared and determined. The film with n-alkyl benzene moieties showed better alignment performance than the others.

A tunable surface-emitting dual-wavelength laser emitted from the blended organic gain layer based on a holographic polymer dispersed liquid crystal (HPDLC) transmission grating feedback structure was reported. The organic blended gain layer was formed from Poly (2-methoxy-5-(2’-ethyl-hexyloxy)-p-phenylenevinylene) (MEH-PPV) and Poly (2-methoxy-5-(3′, 7’-dimethyloctyloxy)-1, 4-phenylenevinylene) (MDMO-PPV) with a weight ratio of 2:1. The dual-wavelength laser located at 629.9 nm and 640 nm was obtained in a single beam. The optical characteristics of these two organic semiconducting materials and the dual-wavelength laser performance under an electric field are investigated and illustrated. This simple tunable dual-wavelength laser shows the potential to extend the development of organic lasers.