本文選題：手性向列相液晶 + 液晶激光器��； 參考：《沈陽理工大學(xué)》2015年碩士論文

【摘要】：液晶激光器是一種將激光染料摻雜到液晶中,并利用光子禁帶或多重散射提供光反饋的新型激光器。由于其特殊的結(jié)構(gòu)和激發(fā)機(jī)制,液晶激光器具有可調(diào)諧、窄線寬、激發(fā)閾值低和尺寸微小等優(yōu)點(diǎn)。這些優(yōu)勢使得液晶激光器在光學(xué)集成、激光顯示、醫(yī)學(xué)和光通訊等領(lǐng)域具有巨大的應(yīng)用前景。本文從理論模擬和實(shí)驗(yàn)兩個(gè)方面對可調(diào)諧液晶激光理論和其產(chǎn)生激光輻射的機(jī)理進(jìn)行了闡述,設(shè)計(jì)制作了溫度調(diào)諧負(fù)性液晶激光器,電場調(diào)諧液晶激光器和染料摻雜聚合物分散液晶激光器。本文采用染料摻雜手性向列相液晶作為增益介質(zhì),器件激光輻射機(jī)制為光子禁帶末端激光(Band-edge Lasing)。論文在光子晶體理論基礎(chǔ)上討論了平面織構(gòu)態(tài)手性向列相液晶結(jié)構(gòu)特點(diǎn),并利用Berreman’s 4×4矩陣模擬了平面織構(gòu)態(tài)手性向列相液晶器件的透射特性,基于布拉格選擇反射理論討論了其光子禁帶特性。采用染料摻雜負(fù)性手性向列相液晶設(shè)計(jì)制作了溫度調(diào)諧液晶激光器,利用楔形液晶盒測量了其螺距隨溫度的變化,發(fā)現(xiàn)本文使用的負(fù)性手性向列相液晶螺距隨溫度升高而增加。當(dāng)溫度從20℃升高到67℃時(shí),輸出波長從614.4 nm紅移到662.8nm,器件光子禁帶中心波長也隨之紅移且禁帶寬度逐漸變窄。設(shè)計(jì)了兩種電極結(jié)構(gòu)對正性和負(fù)性手性向列相液晶激光器分別施加垂直螺旋軸和平行螺旋軸方向的電場。從器件織構(gòu)、透射譜、激光輸出特性等方面分析了液晶激光器件的電場調(diào)諧特性,正性和負(fù)性液晶激光器分別獲得范圍約為8nm和18.5nm的電場調(diào)諧激光輸出。采用微膠囊法制備了聚合物分散液晶薄膜激光器,研究了其激光輻射機(jī)制和溫度調(diào)諧特性。器件中液晶微滴尺寸約為80μm,且微滴中液晶分子呈現(xiàn)平面織構(gòu)態(tài)。以532nm Nd:YAG激光器作為泵浦源,在634.5nm和680.2nm波長處獲得了窄線寬激光輻射峰,線寬分別約為0.25nm、0.29nm。升高器件溫度其輸出激光波長從666.7nm藍(lán)移至643.9nm,共獲得22.8nm的調(diào)諧激光輸出。
[Abstract]:Liquid crystal laser (LCLL) is a new type of laser which is doped with laser dyes and provides optical feedback by photonic bandgap or multiple scattering. Because of its special structure and excitation mechanism, liquid crystal laser has the advantages of tunable, narrow linewidth, low excitation threshold and small size. These advantages make liquid crystal lasers have great application prospects in optical integration, laser display, medicine and optical communication. In this paper, the theory of tunable liquid crystal laser and its mechanism of producing laser radiation are described from the aspects of theoretical simulation and experiment, and the temperature tunable negative liquid crystal laser is designed and fabricated. Electric field tunable liquid crystal laser and dye doped polymer dispersed liquid crystal laser. Dye-doped chiral nematic liquid crystal is used as gain medium. The laser radiation mechanism of the device is Band-edge laser at the end of photonic bandgap. On the basis of photonic crystal theory, the structure characteristics of planar texture chiral nematic liquid crystal are discussed, and the transmission characteristics of planar texture chiral nematic liquid crystal devices are simulated by Berreman's 4 脳 4 matrix. The photonic band gap is discussed based on Bragg selective reflection theory. The temperature tunable liquid crystal laser was fabricated by using dyestuff doped chiral nematic liquid crystal. The pitch of the liquid crystal with temperature was measured by using a wedge liquid crystal cell. It was found that the pitch of the chiral nematic liquid crystal increased with the increase of temperature. When the temperature is raised from 20 鈩，

本文編號：1815848