激(ji)(ji)(ji)(ji)(ji)(ji)(ji)光(guang)(guang)(guang)(guang)顯(xian)(xian)(xian)(xian)(xian)(xian)(xian)示(shi)(shi)(shi)(shi)(shi)可(ke)以真實地再(zai)現(xian)(xian)客觀世界豐富、艷麗的(de)(de)(de)(de)(de)(de)色(se)(se)(se)彩,具有(you)震(zhen)撼的(de)(de)(de)(de)(de)(de)表現(xian)(xian)力,被稱為(wei)(wei)(wei)第四代(dai)(dai)顯(xian)(xian)(xian)(xian)(xian)(xian)(xian)示(shi)(shi)(shi)(shi)(shi)技術．與人(ren)(ren)眼(yan)所見的(de)(de)(de)(de)(de)(de)自然光(guang)(guang)(guang)(guang)色(se)(se)(se)域(yu)相比,傳統(tong)顯(xian)(xian)(xian)(xian)(xian)(xian)(xian)示(shi)(shi)(shi)(shi)(shi)設備只能(neng)再(zai)現(xian)(xian)30%,而激(ji)(ji)(ji)(ji)(ji)(ji)(ji)光(guang)(guang)(guang)(guang)顯(xian)(xian)(xian)(xian)(xian)(xian)(xian)示(shi)(shi)(shi)(shi)(shi)可(ke)以覆蓋90%的(de)(de)(de)(de)(de)(de)色(se)(se)(se)域(yu),色(se)(se)(se)彩飽和度(du)是傳統(tong)顯(xian)(xian)(xian)(xian)(xian)(xian)(xian)示(shi)(shi)(shi)(shi)(shi)設備的(de)(de)(de)(de)(de)(de)100倍以上．此外,激(ji)(ji)(ji)(ji)(ji)(ji)(ji)光(guang)(guang)(guang)(guang)顯(xian)(xian)(xian)(xian)(xian)(xian)(xian)示(shi)(shi)(shi)(shi)(shi)還(huan)能(neng)夠實現(xian)(xian)圖像幾何(he)、顏色(se)(se)(se)的(de)(de)(de)(de)(de)(de)雙高(gao)清和真三維顯(xian)(xian)(xian)(xian)(xian)(xian)(xian)示(shi)(shi)(shi)(shi)(shi),是實現(xian)(xian)高(gao)保真圖像的(de)(de)(de)(de)(de)(de)最佳方(fang)式．因此,激(ji)(ji)(ji)(ji)(ji)(ji)(ji)光(guang)(guang)(guang)(guang)顯(xian)(xian)(xian)(xian)(xian)(xian)(xian)示(shi)(shi)(shi)(shi)(shi)也被稱為(wei)(wei)(wei)“人(ren)(ren)類視覺史上的(de)(de)(de)(de)(de)(de)革命”．1966年(nian),Korpel等(deng)首次提(ti)出將激(ji)(ji)(ji)(ji)(ji)(ji)(ji)光(guang)(guang)(guang)(guang)作(zuo)為(wei)(wei)(wei)顯(xian)(xian)(xian)(xian)(xian)(xian)(xian)示(shi)(shi)(shi)(shi)(shi)光(guang)(guang)(guang)(guang)源(yuan)的(de)(de)(de)(de)(de)(de)想法,隨后各國研究人(ren)(ren)員紛(fen)紛(fen)投入(ru)到(dao)激(ji)(ji)(ji)(ji)(ji)(ji)(ji)光(guang)(guang)(guang)(guang)顯(xian)(xian)(xian)(xian)(xian)(xian)(xian)示(shi)(shi)(shi)(shi)(shi)的(de)(de)(de)(de)(de)(de)研究大潮(chao)中．激(ji)(ji)(ji)(ji)(ji)(ji)(ji)光(guang)(guang)(guang)(guang)顯(xian)(xian)(xian)(xian)(xian)(xian)(xian)示(shi)(shi)(shi)(shi)(shi)技術的(de)(de)(de)(de)(de)(de)出現(xian)(xian),也為(wei)(wei)(wei)我(wo)國在(zai)顯(xian)(xian)(xian)(xian)(xian)(xian)(xian)示(shi)(shi)(shi)(shi)(shi)領(ling)域(yu)的(de)(de)(de)(de)(de)(de)發展提(ti)供(gong)了(le)新的(de)(de)(de)(de)(de)(de)契機(ji)．為(wei)(wei)(wei)了(le)進(jin)一(yi)步(bu)推動我(wo)國激(ji)(ji)(ji)(ji)(ji)(ji)(ji)光(guang)(guang)(guang)(guang)顯(xian)(xian)(xian)(xian)(xian)(xian)(xian)示(shi)(shi)(shi)(shi)(shi)產業(ye)的(de)(de)(de)(de)(de)(de)發展,２０世紀８０年(nian)代(dai)(dai),我(wo)國提(ti)出激(ji)(ji)(ji)(ji)(ji)(ji)(ji)光(guang)(guang)(guang)(guang)全色(se)(se)(se)顯(xian)(xian)(xian)(xian)(xian)(xian)(xian)示(shi)(shi)(shi)(shi)(shi)的(de)(de)(de)(de)(de)(de)國家863計劃,圍繞激(ji)(ji)(ji)(ji)(ji)(ji)(ji)光(guang)(guang)(guang)(guang)顯(xian)(xian)(xian)(xian)(xian)(xian)(xian)示(shi)(shi)(shi)(shi)(shi)技術成立了(le)產業(ye)聯(lian)盟．激(ji)(ji)(ji)(ji)(ji)(ji)(ji)光(guang)(guang)(guang)(guang)顯(xian)(xian)(xian)(xian)(xian)(xian)(xian)示(shi)(shi)(shi)(shi)(shi)的(de)(de)(de)(de)(de)(de)光(guang)(guang)(guang)(guang)源(yuan)歷經氣體(ti)激(ji)(ji)(ji)(ji)(ji)(ji)(ji)光(guang)(guang)(guang)(guang)器、固態激(ji)(ji)(ji)(ji)(ji)(ji)(ji)光(guang)(guang)(guang)(guang)器后,又迎來了(le)半(ban)(ban)導(dao)體(ti)激(ji)(ji)(ji)(ji)(ji)(ji)(ji)光(guang)(guang)(guang)(guang)器時(shi)代(dai)(dai)．進(jin)入(ru)２１世紀后,半(ban)(ban)導(dao)體(ti)激(ji)(ji)(ji)(ji)(ji)(ji)(ji)光(guang)(guang)(guang)(guang)器技術全面發展,器件(jian)(jian)的(de)(de)(de)(de)(de)(de)功率和性能(neng)都(dou)有(you)了(le)大幅度(du)的(de)(de)(de)(de)(de)(de)提(ti)高(gao),作(zuo)為(wei)(wei)(wei)激(ji)(ji)(ji)(ji)(ji)(ji)(ji)光(guang)(guang)(guang)(guang)顯(xian)(xian)(xian)(xian)(xian)(xian)(xian)示(shi)(shi)(shi)(shi)(shi)的(de)(de)(de)(de)(de)(de)光(guang)(guang)(guang)(guang)源(yuan)則更具競(jing)爭力．半(ban)(ban)導(dao)體(ti)激(ji)(ji)(ji)(ji)(ji)(ji)(ji)光(guang)(guang)(guang)(guang)器可(ke)直(zhi)接(jie)由電流激(ji)(ji)(ji)(ji)(ji)(ji)(ji)勵,比固態激(ji)(ji)(ji)(ji)(ji)(ji)(ji)光(guang)(guang)(guang)(guang)器的(de)(de)(de)(de)(de)(de)效率更高(gao);工作(zuo)物質(zhi)衰減(jian)較(jiao)慢,使(shi)(shi)用壽命更長;光(guang)(guang)(guang)(guang)源(yuan)系統(tong)的(de)(de)(de)(de)(de)(de)體(ti)積(ji)更小,適合(he)高(gao)度(du)集成;利(li)用半(ban)(ban)導(dao)體(ti)工藝規(gui)模化(hua)生產,可(ke)使(shi)(shi)器件(jian)(jian)成本更低。

　　激光顯示(shi)對紅光光源的要(yao)求

　　激(ji)光(guang)(guang)顯(xian)示系統對于(yu)紅光(guang)(guang)光(guang)(guang)源的(de)(de)(de)(de)(de)(de)(de)波(bo)(bo)長(chang)選(xuan)擇主(zhu)要考慮(lv)兩個方(fang)面的(de)(de)(de)(de)(de)(de)(de)因素(su):１)根據人眼(yan)(yan)對波(bo)(bo)長(chang)的(de)(de)(de)(de)(de)(de)(de)響應(ying)(ying)度(du)來(lai)選(xuan)擇人眼(yan)(yan)敏(min)感的(de)(de)(de)(de)(de)(de)(de)波(bo)(bo)長(chang),以獲得(de)較高的(de)(de)(de)(de)(de)(de)(de)光(guang)(guang)視(shi)效能(neng)(neng);２)所選(xuan)波(bo)(bo)長(chang)能(neng)(neng)夠擴大色域的(de)(de)(de)(de)(de)(de)(de)覆(fu)蓋范圍(wei),從而獲得(de)更好的(de)(de)(de)(de)(de)(de)(de)色彩(cai)體(ti)驗．對于(yu)大于(yu)600nm的(de)(de)(de)(de)(de)(de)(de)紅色激(ji)光(guang)(guang),波(bo)(bo)長(chang)越(yue)(yue)短,則光(guang)(guang)視(shi)效能(neng)(neng)越(yue)(yue)高;波(bo)(bo)長(chang)越(yue)(yue)長(chang),則色域覆(fu)蓋的(de)(de)(de)(de)(de)(de)(de)范圍(wei)越(yue)(yue)大．根據國家電視(shi)標準委員會(hui)(NTSC)的(de)(de)(de)(de)(de)(de)(de)標準,當選(xuan)用(yong)620nm紅光(guang)(guang)時(shi),光(guang)(guang)視(shi)效能(neng)(neng)為0．33lm/W,此(ci)時(shi)的(de)(de)(de)(de)(de)(de)(de)色域可達161%;當選(xuan)用(yong)650nm的(de)(de)(de)(de)(de)(de)(de)紅光(guang)(guang)時(shi),色域高達211%,光(guang)(guang)視(shi)效能(neng)(neng)則降為0．141lm/W．所以,在實際應(ying)(ying)用(yong)中,需要綜合(he)考慮(lv)激(ji)光(guang)(guang)顯(xian)示應(ying)(ying)用(yong)的(de)(de)(de)(de)(de)(de)(de)場景和光(guang)(guang)源系統的(de)(de)(de)(de)(de)(de)(de)性能(neng)(neng),來(lai)選(xuan)擇合(he)適(shi)的(de)(de)(de)(de)(de)(de)(de)激(ji)光(guang)(guang)波(bo)(bo)長(chang)．目前,國際上用(yong)于(yu)激(ji)光(guang)(guang)顯(xian)示的(de)(de)(de)(de)(de)(de)(de)紅光(guang)(guang)波(bo)(bo)長(chang)通常集中在630～650nm,其中638nm紅光(guang)(guang)半(ban)導體(ti)激(ji)光(guang)(guang)器的(de)(de)(de)(de)(de)(de)(de)綜合(he)性能(neng)(neng)最好。

　　激(ji)(ji)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)顯(xian)(xian)(xian)示所需的(de)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)源(yuan)功率等(deng)于(yu)屏幕(mu)亮(liang)度除(chu)以(yi)(yi)激(ji)(ji)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)源(yuan)的(de)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)視效能,而屏幕(mu)亮(liang)度等(deng)于(yu)環境亮(liang)度乘以(yi)(yi)屏幕(mu)面積(ji)(ji)再除(chu)以(yi)(yi)屏幕(mu)的(de)對(dui)比度．簡單來說,A４紙大(da)小(xiao)的(de)屏幕(mu),為保證正常的(de)投影(ying)(ying)需要(yao)(yao),紅光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)半(ban)導體(ti)激(ji)(ji)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)器的(de)輸(shu)出(chu)功率約為50mW;40inch(101．6cm)的(de)屏幕(mu),輸(shu)出(chu)功率則至少達(da)到(dao)(dao)500mW;而對(dui)于(yu)大(da)尺寸(cun)屏幕(mu),光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)通量在1000lm以(yi)(yi)上時,則輸(shu)出(chu)功率需要(yao)(yao)達(da)到(dao)(dao)25W以(yi)(yi)上．隨(sui)著(zhu)紅光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)半(ban)導體(ti)激(ji)(ji)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)器的(de)發(fa)展,器件的(de)輸(shu)出(chu)功率已有了(le)大(da)幅度的(de)提升,目(mu)前商(shang)用的(de)638nm紅光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)半(ban)導體(ti)激(ji)(ji)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)器的(de)功率水(shui)平(ping)已達(da)到(dao)(dao)瓦級(ji),通過光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)合束(shu)(shu)處理,功率水(shui)平(ping)可以(yi)(yi)滿足大(da)部分(fen)激(ji)(ji)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)顯(xian)(xian)(xian)示的(de)應(ying)(ying)(ying)用需求(qiu)．激(ji)(ji)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)顯(xian)(xian)(xian)示對(dui)于(yu)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)源(yuan)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)束(shu)(shu)質量的(de)要(yao)(yao)求(qiu)主要(yao)(yao)取決于(yu)所使(shi)用的(de)激(ji)(ji)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)顯(xian)(xian)(xian)示技術(shu)．目(mu)前,主流的(de)激(ji)(ji)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)顯(xian)(xian)(xian)示技術(shu)分(fen)為３類:激(ji)(ji)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)線(xian)掃描(miao)、激(ji)(ji)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)點掃描(miao)和激(ji)(ji)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)投影(ying)(ying)．激(ji)(ji)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)線(xian)掃描(miao)體(ti)積(ji)(ji)和效率介(jie)于(yu)激(ji)(ji)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)投影(ying)(ying)和點掃描(miao)之間,該技術(shu)主要(yao)(yao)應(ying)(ying)(ying)用在微投影(ying)(ying)領域;激(ji)(ji)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)點掃描(miao)效率較(jiao)(jiao)高、體(ti)積(ji)(ji)小(xiao),整個系(xi)統(tong)的(de)成本較(jiao)(jiao)低,但是(shi)對(dui)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)源(yuan)的(de)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)束(shu)(shu)質量和調(diao)制系(xi)統(tong)的(de)要(yao)(yao)求(qiu)較(jiao)(jiao)高,亮(liang)度低,只能適合于(yu)小(xiao)尺寸(cun)(小(xiao)于(yu)A４紙)的(de)顯(xian)(xian)(xian)示應(ying)(ying)(ying)用．激(ji)(ji)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)投影(ying)(ying)技術(shu)對(dui)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)源(yuan)的(de)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)束(shu)(shu)質量要(yao)(yao)求(qiu)不高,人(ren)眼安全范圍內允許的(de)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)(guang)通量較(jiao)(jiao)大(da),適合于(yu)大(da)部分(fen)顯(xian)(xian)(xian)示領域．

　　寬條形(xing)結(jie)構(gou)(gou)是大(da)功率(lv)(lv)激光(guang)器常(chang)用(yong)(yong)設計(ji),如圖b是常(chang)見的(de)(de)折(zhe)(zhe)射(she)率(lv)(lv)導引結(jie)構(gou)(gou)的(de)(de)芯片結(jie)構(gou)(gou)。利用(yong)(yong)材料折(zhe)(zhe)射(she)率(lv)(lv)差導引的(de)(de)結(jie)構(gou)(gou)不僅對注入電流(liu)和載流(liu)子的(de)(de)側向擴散(san)有(you)限(xian)制(zhi)作(zuo)用(yong)(yong),還(huan)能夠(gou)限(xian)制(zhi)光(guang)場的(de)(de)側向滲透．所以折(zhe)(zhe)射(she)率(lv)(lv)導引機制(zhi)能夠(gou)有(you)效降(jiang)低器件(jian)的(de)(de)閾值(zhi)電流(liu),同時有(you)源(yuan)區(qu)產生的(de)(de)熱量能夠(gou)向周(zhou)圍(wei)的(de)(de)無源(yuan)區(qu)散(san)失(shi),保持器件(jian)的(de)(de)熱穩定性。

　　紅光激光器的(de)技術難點

　　1、縮短波長

　　紅(hong)光有源區(qu)的(de)(de)(de)(de)(de)(de)主要(yao)(yao)(yao)材料是AlGaInP,襯底GaAs。理論波(bo)(bo)長(chang)(chang)(chang)為(wei)580-680nm。早(zao)期的(de)(de)(de)(de)(de)(de)波(bo)(bo)長(chang)(chang)(chang)大部分在680nm附近,要(yao)(yao)(yao)想(xiang)縮(suo)短波(bo)(bo)長(chang)(chang)(chang)就需要(yao)(yao)(yao)增加(jia)帶隙寬度,增加(jia)Al含量(liang)(liang)(liang)。當增加(jia)Al組分之后,有源區(qu)的(de)(de)(de)(de)(de)(de)帶隙寬度變大,縮(suo)短了器(qi)件的(de)(de)(de)(de)(de)(de)激射波(bo)(bo)長(chang)(chang)(chang),但同時也減(jian)小(xiao)了有源區(qu)和P區(qu)的(de)(de)(de)(de)(de)(de)能(neng)量(liang)(liang)(liang)差,加(jia)劇(ju)了有源區(qu)載流子(zi)的(de)(de)(de)(de)(de)(de)泄漏,提高了器(qi)件的(de)(de)(de)(de)(de)(de)閾值(zhi)電流．在縮(suo)短AlGaInP波(bo)(bo)長(chang)(chang)(chang)方(fang)面,主要(yao)(yao)(yao)通(tong)過增加(jia)有源區(qu)中Al的(de)(de)(de)(de)(de)(de)含量(liang)(liang)(liang)、采用量(liang)(liang)(liang)子(zi)阱(jing)結構、量(liang)(liang)(liang)子(zi)阱(jing)混雜(za)等方(fang)式實現．紅(hong)光半(ban)導(dao)體激光器(qi)的(de)(de)(de)(de)(de)(de)波(bo)(bo)長(chang)(chang)(chang)越短,制(zhi)作難度越大、性能(neng)也越差,這(zhe)些是限制(zhi)短波(bo)(bo)長(chang)(chang)(chang)紅(hong)光半(ban)導(dao)體激光器(qi)發展的(de)(de)(de)(de)(de)(de)主要(yao)(yao)(yao)原因,也是研究(jiu)人(ren)員(yuan)急需解(jie)決的(de)(de)(de)(de)(de)(de)問(wen)題．

　　２提高(gao)器件(jian)的輸(shu)出功率

　　影響(xiang)激(ji)(ji)(ji)光器(qi)(qi)功率(lv)(lv)提(ti)高的(de)(de)主要因素是腔(qiang)(qiang)面災變性光學損傷(COMD)．COMD主要發生(sheng)在(zai)激(ji)(ji)(ji)光器(qi)(qi)的(de)(de)出(chu)光腔(qiang)(qiang)面上(shang),在(zai)輸出(chu)功率(lv)(lv)較大(da)時,腔(qiang)(qiang)面的(de)(de)光功率(lv)(lv)密度(du)增(zeng)(zeng)大(da),當AlGaInP激(ji)(ji)(ji)光器(qi)(qi)的(de)(de)腔(qiang)(qiang)面功率(lv)(lv)密度(du)達到(dao)１～５MW/cm２時,激(ji)(ji)(ji)光器(qi)(qi)腔(qiang)(qiang)面處的(de)(de)缺(que)陷數量就會不斷增(zeng)(zeng)加,并向內部遷(qian)移,導致(zhi)激(ji)(ji)(ji)光器(qi)(qi)發生(sheng)COMD,輸出(chu)功率(lv)(lv)急(ji)速下降．研究人員經(jing)過(guo)大(da)量的(de)(de)理(li)論分析和實踐探索,發現(xian)在(zai)激(ji)(ji)(ji)光器(qi)(qi)腔(qiang)(qiang)面制(zhi)作(zuo)非吸收窗口(kou)結構(gou)可以(yi)有(you)效抑制(zhi)COMD現(xian)象(xiang)。通(tong)過(guo)快速退(tui)火的(de)(de)方式將Zn作(zuo)為雜質擴(kuo)散到(dao)有(you)源(yuan)區(qu)(qu),Zn擴(kuo)散加強(qiang)了(le)AlGaInP自(zi)然超晶(jing)格的(de)(de)無序性,也增(zeng)(zeng)加了(le)擴(kuo)散區(qu)(qu)量子阱的(de)(de)能帶寬度(du)．而有(you)源(yuan)區(qu)(qu)以(yi)外帶隙寬度(du)較小的(de)(de)區(qu)(qu)域無法吸收振蕩的(de)(de)激(ji)(ji)(ji)光,稱為窗口(kou)區(qu)(qu)．非吸收窗口(kou)的(de)(de)出(chu)現(xian)大(da)大(da)降低了(le)整個發光區(qu)(qu)的(de)(de)溫(wen)度(du),有(you)效抑制(zhi)了(le)COMD現(xian)象(xiang)．下圖為帶有(you)窗口(kou)結構(gou)的(de)(de)半導體(ti)激(ji)(ji)(ji)光器(qi)(qi)．