技術文章
TECHNICAL ARTICLES1. 中(zhong)國(guo)科學院 重慶綠色(se)智能技術研究(jiu)院 Zhongbo Yang等
Near-Field Nanoscopic Terahertz Imaging of Single Proteins. Small.
Figure 1. Schematic illustration of the THz s-SNOM setup and its use for single biomolecule imaging.
Figure 2. THz near-field signals collected on different substrates. a) Time-domain THz electric field signals, and b) corresponding frequency-domain signals collected on graphene, Au, Si, and mica surfaces, respectively. The signals were demodulated at the second harmonics (2 Ω) of the probe oscillation frequency. c,d) The AFM topography images of graphene and Au substrates with 200 × 200 pixels, respectively. The height scale bars of (c) and (d) are the same.
摘要:太赫茲生物成像因其能以無標記、無創傷和非電離的方式獲取樣品的物理化學信息而頗受矚目。但是,低介電常數生物分子的反射率問題,使得單分子精度的太赫茲成像仍是個挑戰。針對于此,作者開發了種方法,用石墨烯介導的太赫茲頻率散射型掃描近場光學顯微鏡,對(dui)單(dan)個蛋(dan)(dan)白(bai)(bai)分(fen)(fen)子(zi)直(zhi)接成像。此項研究發現,擁有(you)較(jiao)高太赫茲反(fan)射(she)(she)率和(he)原子(zi)平整度(du)的(de)(de)石墨烯基底可以為蛋(dan)(dan)白(bai)(bai)分(fen)(fen)子(zi)提供(gong)較(jiao)高的(de)(de)太赫茲對(dui)比度(du)。另外,我們還(huan)發現對(dui)鉑探針的(de)(de)軸長化能增強太赫茲散射(she)(she)近場(chang)信(xin)號中的(de)(de)振幅信(xin)號強度(du)。基于(yu)這兩個效應,作者同時獲得了(le)尺寸只有(you)數納米的(de)(de)免疫球蛋(dan)(dan)白(bai)(bai)G(IgG)和(he)鐵蛋(dan)(dan)白(bai)(bai)分(fen)(fen)子(zi)的(de)(de)形貌以及太赫茲散射(she)(she)圖(tu)像。本文中所用(yong)的(de)(de)方法為單(dan)生物(wu)分(fen)(fen)子(zi)的(de)(de)太赫茲成像提供(gong)了(le)新思路。
2. 華中科技大學 Chao Chen等
Terahertz Nanoimaging and Nanospectroscopy of Chalcogenide Phase-Change Materials. ACS Photonics 2020.
Figure 2. THz near-field setup and imaging experiments. (a) Schematics of the THz s-SNOM setup with a bolometer used as a detector. The inset shows an illustration of the finite dipole model for the layered sample. (b) Approach curve, showing the amplitude signal s2 on c-GST as a function of tip–sample distance. The mark h1/e represents the position at which the signal decays to 1/e of its maximum. The inset displays an optical microscope image of the AFM tip above the sample. The red dotted squares mark the c-GST areas. (c) AFM topography image (top panel) of GST on a silicon oxide substrate, which includes amorphous and crystalline states. Near-field amplitude (s2, middle panel) and phase (φ2, bottom panel) images at 1.89 THz. (d) Topography, (e) near-field amplitude, and (f) phase line profiles (shown as solid symbols) taken from the corresponding images in c. The red solid lines are smoothed curves based on the experimental data. Horizontal dashed gray lines are a guide for the eye.
摘要:硫屬化物相變材料(PCMs)在太赫茲(THz)頻率下會發生光學聲子共振現象,這個效應可被用于研究相變的基本性,并產生很強的介電對比度,使其可被用于太赫茲的光子學應用。在本文中,我們證明可以通過頻率可調的太赫茲散射型掃描近場光學顯微鏡(s-SNOM)研究PCM的(de)(de)(de)聲子。其(qi)具(ju)體方法(fa)為對(dui)包含非晶相(xiang)和結(jie)晶相(xiang)的(de)(de)(de)PCM樣(yang)品(pin)進行太赫茲(zi)納米光(guang)(guang)譜(pu)成(cheng)像(xiang)。我(wo)(wo)(wo)們(men)觀察到(dao)材料的(de)(de)(de)聲子征使(shi)其(qi)產生了很強(qiang)的(de)(de)(de)s-SNOM信(xin)號,以(yi)(yi)及重要的(de)(de)(de)是(shi),非晶態和結(jie)晶態PCM的(de)(de)(de)光(guang)(guang)譜(pu)之間存在明顯的(de)(de)(de)差異,這使(shi)我(wo)(wo)(wo)們(men)可以(yi)(yi)在納米尺度(du)(du)上高信(xin)度(du)(du)地區(qu)分PCM的(de)(de)(de)不同相(xiang)。我(wo)(wo)(wo)們(men)還(huan)發現可以(yi)(yi)通過增加(jia)針尖的(de)(de)(de)半(ban)徑來增強(qiang)以(yi)(yi)信(xin)號強(qiang)度(du)(du)和頻譜(pu)對(dui)比(bi)度(du)(du)為標志的(de)(de)(de)光(guang)(guang)譜(pu)征。綜上所述,我(wo)(wo)(wo)們(men)用太赫茲(zi)s-SNOM成(cheng)功(gong)構建了基(ji)于(yu)局部聲子光(guang)(guang)譜(pu)的(de)(de)(de)納米結(jie)構以(yi)(yi)及化學組成(cheng)的(de)(de)(de)圖譜(pu)。
3. 中國地質大學-武漢 Zhigao Dai等人
Edge-oriented and steerable hyperbolic polaritons in anisotropic van der Waals nanocavities. Nat. Commun..
Figure 1. a Schematic diagram of edge-tailored PhPs in α-MoO3. The edge orientation is defined as angle θ with respect to the [001] direction. Green arrows indicate the incident PhPs waves launched by the laser-illuminated (purple curve arrows) AFM tip and reflected by the edge (red line). b Angle-dependent ke isofrequency contour of PhPs in α-MoO3 at ω?=?889.8?cm?1. The solid lines and points stand for experimental results concluded from Fig. 1c. The green and black dotted arrows illustrate the incidence wavevector ki and Poynting vector Si, respectively. Generally, ki and Si are non-collinear. The reflected Poynting vector Se (solid arrows) is not parallel to the reflected wavevector ke (different color solid arrows) but antiparallel to Si. σ is the open angle. c Real-space imaging of edge-tailoring PhPs at angle-dependent α-MoO3 edges (length L: 2.5?µm; width W: 200?nm; sample thickness d: 210?nm, L and W defined in the Ed1). d s-SNOM line traces along the direction perpendicular to the edges in Ed1-Ed5. e Near-field amplitude s(ω) of PhPs on isosceles triangle α-MoO3 nanocavities with bottom edge perpendicular to the [001] crystal direction (height length: 4.33?μm; thickness: d?=?175?nm); The angles between adjacent sides of the series of triangles with respect to the [001] direction are approximately 7.5°, 15°, 30°, 45°, and 60°, respectively.
摘要:高度受限和低損耗的化子在石墨烯和六方氮化硼上是沿平面各向同性傳播的,這使得對光的控制被限制在了有限的自由度內。而以α-MoO3 and V2O5為代表的新興雙軸范德華材料則展現出了*的化傳播性,它們的輔助光軸是在平面上的。用這種強平面各向異性,作者通過空間納米成像觀測到了α-MoO3納米腔的圖樣內有著受邊界導向的雙曲化子。并且發現邊界的夾角和結晶方向對其光學響應信號有著舉足輕重的影響,這對調整化圖樣的參數是至關重要的。基于此,通過調整α-MoO3納米(mi)(mi)腔的幾(ji)何構型,我們觀測到了雙曲化(hua)子(zi)會(hui)延(yan)邊界傳(chuan)播并(bing)且會(hui)調整自身傳(chuan)播方向的性以(yi)及與(yu)之對應(ying)的化(hua)子(zi)繞行禁(jin)·區。而(er)這種雙曲化(hua)子(zi)的壽命和(he)性能(neng)指數則受到納米(mi)(mi)腔邊界寬(kuan)高比的限(xian)制。
4. 國防科學技術大學 Jiangyu Zhang 等人
Light-induced irreversible structural phase transition in trilayer graphene. Sci. & App..
Figure 4. Raman mapping and s-SNOM imaging of the light-induced structural phase transition in MLG. (a) Optical microscopy image of MLG sample #125. (b) AFM image and height profile of graphene. (c) Raman maps of the integrated G peak intensity (position: 1576?cm?1, width: 5?cm?1) before laser irradiation and (d) after laser irradiation. The laser power is 20?mW, and the exposure time is 34?min. (e) s-SNOM image of graphene after laser irradiation. (f) Magnified s-SNOM image of graphene. Graphene domains with different stacking orders show different contrasts in the s-SNOM image. The marked regions I, II, and III correspond to ABC stacking, ABA stacking and mixed ABC?+?ABA stacking domains, respectively. The red arrows in (e, f) highlight the additional mixed ABC?+?ABA stacking domains that were not resolved in the Raman maps. (g) Raman spectra of different graphene regions taken from the marked solid dots before laser irradiation and (h) after laser irradiation
摘要:晶(jing)(jing)體結(jie)(jie)構(gou)(gou)(gou)(gou)(gou)對(dui)(dui)相關材(cai)料的(de)(de)(de)(de)(de)(de)物理(li)性(xing)質有(you)(you)(you)著深刻的(de)(de)(de)(de)(de)(de)影(ying)響。因此,即使化學組成(cheng)相同(比如(ru)石(shi)(shi)墨(mo)烯和金(jin)剛石(shi)(shi)),我們(men)也可(ke)(ke)以通(tong)過(guo)生(sheng)成(cheng)具(ju)有(you)(you)(you)定對(dui)(dui)稱性(xing)的(de)(de)(de)(de)(de)(de)晶(jing)(jing)體,來很(hen)大范(fan)圍內(nei)調(diao)整(zheng)(zheng)它們(men)的(de)(de)(de)(de)(de)(de)性(xing)。而(er)當晶(jing)(jing)體的(de)(de)(de)(de)(de)(de)結(jie)(jie)構(gou)(gou)(gou)(gou)(gou)相可(ke)(ke)以通(tong)過(guo)外部(bu)刺激動態(tai)改變(bian)時,更(geng)多(duo)有(you)(you)(you)意思的(de)(de)(de)(de)(de)(de)可(ke)(ke)能(neng)性(xing)出(chu)現(xian)(xian)(xian)(xian)在(zai)了我們(men)面前。這(zhe)(zhe)樣的(de)(de)(de)(de)(de)(de)材(cai)料性(xing)雖(sui)不(bu)常見,但卻能(neng)引發(fa)很(hen)多(duo)喜(xi)人的(de)(de)(de)(de)(de)(de)現(xian)(xian)(xian)(xian)象(xiang),例如(ru)相變(bian)記憶效應。具(ju)體到三層石(shi)(shi)墨(mo)烯,它有(you)(you)(you)兩(liang)種常見的(de)(de)(de)(de)(de)(de)堆(dui)疊結(jie)(jie)構(gou)(gou)(gou)(gou)(gou)(ABA和ABC),二(er)者都(dou)具(ju)有(you)(you)(you)*的(de)(de)(de)(de)(de)(de)電子(zi)能(neng)帶結(jie)(jie)構(gou)(gou)(gou)(gou)(gou),并展(zhan)現(xian)(xian)(xian)(xian)出(chu)了與眾不(bu)同的(de)(de)(de)(de)(de)(de)性(xing)。而(er)這(zhe)(zhe)兩(liang)種堆(dui)疊結(jie)(jie)構(gou)(gou)(gou)(gou)(gou)的(de)(de)(de)(de)(de)(de)三層石(shi)(shi)墨(mo)烯里(li)的(de)(de)(de)(de)(de)(de)疇(chou)壁,則展(zhan)現(xian)(xian)(xian)(xian)出(chu)了新(xin)的(de)(de)(de)(de)(de)(de)迷(mi)人的(de)(de)(de)(de)(de)(de)物理(li)效應,比如(ru)說量子(zi)谷霍爾效應。科研工(gong)作者在(zai)三層石(shi)(shi)墨(mo)烯的(de)(de)(de)(de)(de)(de)相工(gong)程上投入(ru)了大量的(de)(de)(de)(de)(de)(de)精力。不(bu)過(guo),操縱(zong)疇(chou)壁以實(shi)現(xian)(xian)(xian)(xian)對(dui)(dui)材(cai)料局(ju)部(bu)結(jie)(jie)構(gou)(gou)(gou)(gou)(gou)和性(xing)的(de)(de)(de)(de)(de)(de)精準調(diao)控仍然是個難題。本(ben)文通(tong)過(guo)實(shi)驗表明,通(tong)過(guo)激光照(zhao)射可(ke)(ke)以實(shi)現(xian)(xian)(xian)(xian)結(jie)(jie)構(gou)(gou)(gou)(gou)(gou)相之間(jian)的(de)(de)(de)(de)(de)(de)轉換,并在(zai)三層石(shi)(shi)墨(mo)烯中構(gou)(gou)(gou)(gou)(gou)建各種形狀的(de)(de)(de)(de)(de)(de)疇(chou)壁。這(zhe)(zhe)種能(neng)夠控制(zhi)疇(chou)壁位置和方向的(de)(de)(de)(de)(de)(de)能(neng)力,使得我們(men)能(neng)夠更(geng)好地(di)調(diao)整(zheng)(zheng)石(shi)(shi)墨(mo)烯的(de)(de)(de)(de)(de)(de)局(ju)部(bu)結(jie)(jie)構(gou)(gou)(gou)(gou)(gou)相和性(xing),并為可(ke)(ke)定制(zhi)原子(zi)結(jie)(jie)構(gou)(gou)(gou)(gou)(gou),電子(zi)以及光學性(xing)的(de)(de)(de)(de)(de)(de)人造二(er)維材(cai)料的(de)(de)(de)(de)(de)(de)生(sheng)成(cheng)提供了種簡潔且有(you)(you)(you)效的(de)(de)(de)(de)(de)(de)路徑。
5. 華中科技大學 Peining Li等人
Collective near-field coupling and nonlocal phenomena in infrared-phononic metasurfaces for nano-light canalization. Nat.Commun..
Figure 2. Near-field imaging of polariton evolution in a hBN metasurface. a Schematic of the near-field nanoimaging experiment. b, c Near-field images measured at two different frequencies, ω?=?1415?cm?1 (HPhP region) and ω?=?1510?cm?1 (EPhP region). White arrows indicate the polariton fringes observed on the metasurface.
摘要:通(tong)過光(guang)子(zi)(zi)耦合(he)激發(fa)和偶物質(zhi)激發(fa)所產生的(de)(de)(de)化(hua)(hua)(hua)(hua)(hua)子(zi)(zi)可以(yi)沿具(ju)有(you)(you)雙曲(qu)線(xian)色(se)(se)散(san)(san)或橢圓色(se)(se)散(san)(san)的(de)(de)(de)各(ge)向(xiang)異性超(chao)表(biao)面(mian)傳(chuan)播。而(er)在(zai)雙曲(qu)線(xian)色(se)(se)散(san)(san)與橢圓色(se)(se)散(san)(san)之間(jian)的(de)(de)(de)轉(zhuan)(zhuan)換(huan)過程(cheng)中(對應拓(tuo)撲結構的(de)(de)(de)轉(zhuan)(zhuan)換(huan)),有(you)(you)各(ge)種(zhong)(zhong)有(you)(you)趣(qu)的(de)(de)(de)現象被觀(guan)測到,比如(ru)光(guang)子(zi)(zi)態密度(du)(du)的(de)(de)(de)增強、化(hua)(hua)(hua)(hua)(hua)子(zi)(zi)的(de)(de)(de)溝道效應和超(chao)透(tou)鏡(jing)效應。在(zai)本文(wen)中,作(zuo)者(zhe)從理論角度(du)(du)和實驗角度(du)(du)分(fen)(fen)別研究了(le)這種(zhong)(zhong)拓(tuo)撲結構的(de)(de)(de)轉(zhuan)(zhuan)換(huan),單(dan)軸紅外聲子(zi)(zi)超(chao)表(biao)面(mian)中的(de)(de)(de)化(hua)(hua)(hua)(hua)(hua)耦合(he)和其強烈的(de)(de)(de)非局域響(xiang)應信(xin)號,以(yi)及(ji)六方氮化(hua)(hua)(hua)(hua)(hua)硼(peng) (hBN) 納(na)米帶的(de)(de)(de)光(guang)柵。 通(tong)過超(chao)高(gao)分(fen)(fen)辨紅外10納(na)米成像,研究者(zhe)觀(guan)察到了(le)六方氮化(hua)(hua)(hua)(hua)(hua)硼(peng)中余輝帶里合(he)成的(de)(de)(de)橫向(xiang)光(guang)學聲子(zi)(zi)的(de)(de)(de)共振(即納(na)米帶強烈的(de)(de)(de)集體(ti)性近(jin)場耦合(he)),這觸發(fa)了(le)從雙曲(qu)線(xian)色(se)(se)散(san)(san)向(xiang)橢圓色(se)(se)散(san)(san)的(de)(de)(de)拓(tuo)撲轉(zhuan)(zhuan)換(huan)。作(zuo)者(zhe)還表(biao)征并可視化(hua)(hua)(hua)(hua)(hua)了(le)躍遷頻率附(fu)近(jin)深(shen)亞(ya)波長通(tong)道模(mo)式的(de)(de)(de)空間(jian)演(yan)化(hua)(hua)(hua)(hua)(hua),該模(mo)式作(zuo)為(wei)(wei)種(zhong)(zhong)準直化(hua)(hua)(hua)(hua)(hua)子(zi)(zi)為(wei)(wei)超(chao)透(tou)鏡(jing)和無衍射(she)傳(chuan)播打(da)下(xia)了(le)基礎(chu)。
6. 山西大學 PengjuYang 等人
Rational electronic control of carbon dioxide reduction over cobalt oxide. J. Cat..
Figure 2. (a) XPS Co 2p of Co3O4 and Co3O4/Al-1(1 wt% Co3O4), (b) XPS Al 2p of Co3O4/Al-1 and Al-1, (c-d) the S-SNOM optical image of Co3O4/Al-1(1 wt% Co3O4) and SNOM amplitude S3 of lines A-E.
摘要:選擇性地將二氧化碳(CO2)還原為燃料和化學品是通過碳中和發展可持續性能源經濟的重點所在。而其中CO2的活化則是重中之重。考慮到電子遷移是這過程的決速步驟,通過調節CO2還原催化劑的電子結構來增強其活性則顯得更為關鍵。不過,人們對催化劑的電子性與活性的內在關系的理解還不是很深入,這也限制了高效CO2還原催化劑的有理論支撐的設計。本文中,作者設計了種以鋁作為電子供體的催化劑-緣體-金屬系統,并以此來調節氧化鈷(Co3O4)催化劑的電子結構。這樣,鋁中的電子便可以高效地通過種超薄且自主形成的Al2O3緣層穿入Co3O4。實驗和理論結果毫無疑問確證了Co3O4的高電子密度有于CO2的吸收和活化,并同時降低了COOH的生成能壘,尤其是CO*中間體的解吸能壘,這大大加速了CO2到CO的光還原反應的動力學進程。相比Co3O4,Co3O4/Al2O3-Al中的Co的周轉頻率要高出很多。其表觀量子產率在420納米處能高達3.8%,這數字超越了大部分文獻中對催化劑的記述。另外,Co3O4 中電子密度的提高也有效地抑制了析氫競相反應。同時對CO的篩選性也從Co3O4的57.9%提高到了Co3O4/Al2O3-Al的82.4%。值得注意的是,通過控制Al的含量和粒徑我們還可以合理調節催化劑的催化效率。綜上,該項研究建立了催化劑的電子結構與其對 CO2 還原反應的催化活性之間的聯系。并且,作者提出的這種Al2O3-Al結構(gou),還(huan)有潛力成(cheng)為其他非均相催化劑(ji)電(dian)子效應研究的全新平臺。
7. 中山大學 Yan Shen等人
Pyramid-Shaped Single-Crystalline Nanostructure of Molybdenum with Excellent Mechanical, Electrical, and Optical Properties. ACS Appl. Mater. Interfaces.
Figure 6. Optical properties of the pyramid-shaped single-crystalline Mo nanostructures. (a, b) AFM topography and the corresponding optical near–field amplitude (third harmonics, at excitation of 633 nm) images of a typical individual, respectively; the insets are the structural models that help to understand this sample’s geometric features.
摘要:定的幾何形貌與改進過的晶體性對微納米尺度材料的開發來說是舉足輕重的。不過,對于高熔點鉬來說,想高質量地生成同時具有單晶性和預設形貌的結構是很困難的。在本文中,作者通過種熱蒸發技術和與之對應的實驗調控,生成了金字塔形的單晶結構鉬。而之后細致的材料表征工作則表明其生長機理遵循的是個包括MoO2分解(jie)、Mo 沉積、島狀單晶形成(cheng)、層狀成(cheng)核和競爭性(xing)(xing)生(sheng)長在內(nei)的(de)連(lian)續(xu)性(xing)(xing)過程。此外(wai),經測(ce)(ce)量(liang)(liang)還(huan)發(fa)(fa)現(xian)這(zhe)(zhe)種生(sheng)成(cheng)物有著(zhu)非(fei)(fei)(fei)常(chang)(chang)秀(xiu)的(de)物理性(xing)(xing)能。比如(ru)通過機械性(xing)(xing)能的(de)測(ce)(ce)量(liang)(liang),發(fa)(fa)現(xian)納(na)(na)米(mi)(mi)結(jie)(jie)構(gou)(gou)的(de)鉬(mu)展現(xian)出了(le)遠高于其(qi)(qi)塊體(ti)材(cai)料的(de)納(na)(na)米(mi)(mi)壓痕硬度(du)(du)(du)、彈(dan)性(xing)(xing)模量(liang)(liang)和拉(la)伸(shen)強(qiang)(qiang)度(du)(du)(du)。而在電(dian)(dian)子性(xing)(xing)的(de)測(ce)(ce)量(liang)(liang)中,這(zhe)(zhe)種材(cai)料的(de)單體(ti)結(jie)(jie)構(gou)(gou)則展現(xian)出了(le)非(fei)(fei)(fei)常(chang)(chang)秀(xiu)的(de)電(dian)(dian)傳輸性(xing)(xing),其(qi)(qi)電(dian)(dian)導能達(da)到(dao)(dao)約0.16 S。所(suo)制(zhi)備的(de)0.02平方厘(li)米(mi)(mi)的(de)膜材(cai)料展現(xian)出了(le)大電(dian)(dian)流電(dian)(dian)子發(fa)(fa)射性(xing)(xing),其(qi)(qi)大電(dian)(dian)流達(da)到(dao)(dao)了(le)33.6毫安(an),其(qi)(qi)電(dian)(dian)流密度(du)(du)(du)則達(da)到(dao)(dao)了(le)1.68安(an)每(mei)(mei)平方厘(li)米(mi)(mi)。同時,通過光學性(xing)(xing)的(de)測(ce)(ce)量(liang)(liang),該團(tuan)隊發(fa)(fa)現(xian)這(zhe)(zhe)種結(jie)(jie)構(gou)(gou)展現(xian)了(le)明顯的(de)電(dian)(dian)磁場定位和增強(qiang)(qiang)效應,這(zhe)(zhe)使(shi)其(qi)(qi)作(zuo)為基(ji)底材(cai)料,非(fei)(fei)(fei)常(chang)(chang)適(shi)合應用于表面(mian)增強(qiang)(qiang)拉(la)曼散射(SERS)。作(zuo)者還(huan)進步討論了(le)對(dui)應的(de)結(jie)(jie)構(gou)(gou)與響(xiang)應信號(hao)之間的(de)關系。文章中提(ti)到(dao)(dao)的(de),包括微納(na)(na)米(mi)(mi)尺度(du)(du)(du),每(mei)(mei)個晶粒中所(suo)蘊含的(de)單晶性(xing)(xing),以及材(cai)料的(de)金(jin)字塔尖形貌在內(nei)的(de),這(zhe)(zhe)些納(na)(na)米(mi)(mi)結(jie)(jie)構(gou)(gou)鉬(mu)的(de)基(ji)礎性(xing)(xing),都(dou)對(dui)其(qi)(qi)物理性(xing)(xing)有著(zhu)正面(mian)的(de)影(ying)響(xiang)。
8. 香港理工大學 Xin Hu等人
Infrared Nanoimaging of Surface Plasmons in Type-II Dirac Semimetal PtTe2 Nanoribbons. ACS Nano..
Figure 6. Near-field images and plasmonic properties of sub-10 nm PtTe2 tapers. (a) Topography of the PtTe2 taper (NT1) with a thickness of 10.4 nm. The inset is the height profile along the white dashed line. (b) Experimental near-field image of NT1 at the laser frequency of 2500 cm–1 (λ0 = 4 μm). (c) Simulated image of the near-field standing-wave pattern corresponding to (b). The standing-wave patterns in the PtTe2 tapers are mimicked by Enf = E0 + r1 exp(2iksp·x1) + r2 exp(2iksp·x2), where x1 and x2 are the perpendicular distances from an arbitrary point in the taper to its two edges. The propagation constant ksp = (2.264 + 0.884i)k0, supposing the permittivity of the 10.4 nm PtTe2 film is identical to the bulk permittivity, and E0 = 1, r1 = r2 = 0.2. (d) Topography of NT2 with a thickness of 5–7 nm. The inset is the height profile along the black dashed line. (e) Near-field optical image of NT2 at the laser frequency of 1400 cm–1 (λ0 = 7.14 μm). (f) Near-field optical image of NT2 at the laser frequency of 2500 cm–1. The domains in NT2 have different layers (L) ranging from 10L (~5 nm) to 13L (~7 nm). All scale bars are 1 μm.
摘要:由二維過渡金屬二硫屬化物制成的拓撲狄拉克半金屬(TMDCs),因其電子傳輸性,在電子和光電設備域的應用得到了廣泛的關注。作為具有強層間相互作用的范德華材料,這種半金屬被期望可以用于支持尚未被實驗證明的層相關等離子體化激元的存在。在本研究中,作者用近場納米成像展示了II型鉑碲狄拉克半金屬(PtTe-2)納米帶和納米薄片中的中紅外等離子體波的延遲和衰減。從近場駐波圖像中總結出的PtTe-2納米帶(厚度為15到25納米)的等離子體模式衰減色散關系被應用于MIR區的PtTe-2介電常數擬合,其結果表明自由載流子和狄拉克費米子都參與了中紅外光和物質的相互作用。而對超薄(小于10納米)PtTe-2等離子體模式的湮滅的觀察和分析使作者發現是PtTe-2與(yu)本征層相關(guan)的(de)光電(dian)性導(dao)致了其無近(jin)場共振圖(tu)像(xiang)的(de)現象。以上結(jie)果為應用TMDC進行MIR區(qu)的(de)光電(dian)探測和調制鋪展了道路。
9. 上海微系統所&長春光機所 Weiliang Ma等人
Broad spectral tuning of ultra-low-loss polaritons in a van der Waals crystal by intercalation. Nat. Mater..
Figure 2. a–c, Near-field amplitude images s3 of an α-V2O5 flake with thickness d?=?105?nm at incident frequencies ω0?=?1,031 (a), 1,026 (b) and 1,020?cm?1 (c). Scale bar in c, 2?μm. d–f, Profiles along the [100] (green lines) and [001] (blue lines) directions, extracted from the near-field amplitude images in a–c, respectively. λp[100] and λp[001] are the polariton wavelengths along the [100] and [001] directions, respectively. g, Dispersion of PhPs along the [100] (green symbols) and [001] (blue symbols) directions in the RB1. Grey lines are guides for the eye. Grey shaded areas indicate the spectral regions outside the RB. a.u., arbitrary units.
Figure 3. a, Illustration of the α-V2O5 lattice structure (orthorhombic) where the red spheres represent oxygen atoms, the blue atoms represent vanadium atoms, and the blue pyramids show the polyhedral structure defined by the oxygen atoms. The crystal structure consists of bilayers of distorted VO5 pyramids stacked along the [010] direction via vdW interactions (interlayer distance c?=?0.44?nm). b, nanoFTIR spectral line scans along the [100] and [001] directions of a α-V2O5 flake showing s3/s3, Au (near-field amplitude s3 normalized on Au, s3,Au) as a function of distance between the tip and the flake edge. Solid horizontal lines mark the approximate transversal optic (TO) phonon modes in α-V2O5 (TO1, 975?cm?1; TO2, 770?cm?1), separating RB1–3. Dashed lines are guides for the eye of signal maxima. The flake thickness is d?=?245?nm. c, Illustration of the α’-(Na)V2O5 lattice structure (orthorhombic) where the red spheres represent oxygen atoms, the blue atoms represent vanadium atoms, the yellow atoms represent sodium atoms and the blue pyramids show the polyhedral structure defined by the oxygen atoms. The crystal structure consists of bilayers of distorted VO5 pyramids with sodium atoms intercalated and stacked along the [010] direction via vdW interactions (interlayer distance c?=?0.48?nm). d, nanoFTIR spectral line scans along the [100] and [001] directions of a α’-(Na)V2O5 flake showing s3/s3, Au (near-field amplitude s3 normalized on Au, s3,Au) as a function of distance between the tip and the flake edge. The solid horizontal line approximately mark the transversal optic phonon mode in α’-(Na)V2O5 (TO, 950?cm?1), defining RB’1. The flake thickness is d?=?150?nm. The scales in the colour bars of b and d are linear.
摘要:性范德華晶體中的聲子化子——種光與晶格振動的耦合——是有在納米尺度上控制能量流動的有力候選者,因為它們有著很強的限制場、各向異性的傳播方式和皮秒的超長壽命。不過,它們狹窄且只適用定材料的光譜響應范圍——也就是剩余射線帶——大地限制了其技術應用。在此,在α-V2O5范德華(hua)半導體(ti)中(zhong)(zhong)嵌入鈉原子(zi)(zi),能增(zeng)(zeng)寬其剩余射線帶(dai),并因此讓(rang)受激(ji)聲子(zi)(zi)化(hua)子(zi)(zi)展(zhan)現出低的(de)(de)(de)損耗率(壽命為(wei)4±?1皮秒),這個(ge)數值(zhi)已經與其在非插層晶體(ti)(壽命為(wei)6±?1皮秒)中(zhong)(zhong)的(de)(de)(de)表現相近。作者預計這種(zhong)(zhong)嵌入方法也能被應用于其他范德華(hua)晶體(ti),從(cong)而提供種(zhong)(zhong)新的(de)(de)(de)用聲子(zi)(zi)化(hua)子(zi)(zi)增(zeng)(zeng)寬中(zhong)(zhong)紅(hong)外區域(yu)頻譜的(de)(de)(de)方法。
10. 中國科學技術大學 Xinzhong Chen
Moiré engineering of electronic phenomena in correlated oxides. Nat. Phys..
Figure 3. a,b, Infrared near-field image of a curved moiré pattern (a) and the corresponding simulation (b). The simulation is generated by multiplying two periodic striped patterns representing MSs and DSs. The white and black dashed lines in b indicate the MS and DS orientations, respectively. c, Line profiles from the blue dashed lines in a and b, exhibiting high consistency between the experimental and the simulated contrast. a.u., arbitrary units. d,e, Infrared near-field image and corresponding AFM image, respectively, showing alternating moiré and non-moiré regions across the LAO twin boundaries (indicated by red dashed lines). The white solid line in e is the AFM height profile. f, Line profile of the nano-infrared contrast along the blue dashed line in d. The different signal levels are marked ‘C’, ‘D’ and ‘M’, which represent constructively strained, destructively strained and mixed strained regions, respectively. g, Simulation of the image in d with the moiré pattern only visible on the right-hand side. Note that the MSs (orientation indicated by white dashed lines) change orientation across the LAO twin boundary (red dashed line), while the DSs (orientation indicated by black dashed lines) are consistently along the LAO [100] direction. The simulation details are shown in Extended Data Fig. 8c.
摘要:近段時間,摩爾紋工程被視為控制凝聚態系統中量子現象的有效途徑。在范德華異質結構中,莫爾紋可以通過相鄰原子層之間的晶格錯位形成,并因此產生長程電子有序的結構。到目前為止,摩爾工程只在堆疊范德華多層結構上有所應用。而在本文中,作者描述了種在LaAlO3基底上外延生長的原型性磁阻氧化物薄膜La0.67Sr0.33MnO3中產生的電子摩爾紋。通過掃描探針納米成像,作者觀察到了薄膜中應變調制的兩種不同的非公度紋的共存和互相影響所產生的微觀摩爾紋。其凈效應表現為La0.67Sr0.33MnO3的(de)(de)電(dian)子(zi)(zi)電(dian)導率和鐵(tie)磁(ci)性直到細(xi)觀尺度都會受周期性摩爾紋(wen)(wen)的(de)(de)調制。我該研(yan)究工(gong)作為在(zai)應(ying)力外延材料中獲得定制的(de)(de)電(dian)子(zi)(zi)紋(wen)(wen)理的(de)(de)空間圖樣開(kai)辟了(le)條潛(qian)在(zai)的(de)(de)道路(lu)。
11. 國家納米中心 Xiangdong Guo
Efficient All-Optical Plasmonic Modulators with Atomically Thin Van Der Waals Heterostructures. Adv. Mater..
Figure 2. The all-optical graphene plasmon waveguide modulation with a thickness of only several atomic layers. a) Schematic diagram of band alignment and the physical mechanism of photocarrier transfer in the hole-doped graphene/MoS2 heterostructure under visible light irradiation. b,c) Near-field images of a graphene/MoS2 heterostructure on SiO2 substrate in the b) absence and c) presence of 633 nm laser irradiation (6 mW cm?2). Dashed lines indicate the graphene edge. d) The plasmon signals extracted from the cut-lines (red and blue lines) in (b) and (c), respectively.
摘要:全光調制器正越來越受矚目,這主要是因為它高速度,低損耗,與高帶寬的本征性,使其在未來的信息通訊技術中可以很好地為對應的電氣元件做更新換代。但是,其較大的能量消耗與尺寸使得其光子間相互作用較弱,從而阻礙了其在非線性光學上的廣泛應用。在本文中,作者通過在石墨烯中摻雜含有光生載流子的單層MoS2生成了原子薄度石墨烯-MoS2異質結構,形成了種高效全光中紅外等離子體波導和自由空間調制器。44 cm-1等離子的調制也通過LED得以呈現,其光強度可以低達0.15 mWcm-1,這數值比通用的石墨烯非線性全光調制器要低4個數量(≈103 mWcm-2)。異質(zhi)(zhi)結(jie)(jie)構(gou)中(zhong)光生(sheng)載(zai)流子(zi)(zi)的(de)(de)超(chao)高速遷移以(yi)及復合的(de)(de)速率(lv)使(shi)得石墨烯等(deng)離子(zi)(zi)體的(de)(de)超(chao)高速調制(zhi)成為了可能(neng)。作者認為,基于范德華異質(zhi)(zhi)結(jie)(jie)構(gou)的(de)(de)帶有芯片(pian)可集成性和深亞(ya)波長光場(chang)限制(zhi)性的(de)(de)高效全光中(zhong)紅外等(deng)離子(zi)(zi)體調制(zhi)器(qi)的(de)(de)開發或許(xu)向片(pian)上全光器(qi)件應用的(de)(de)實現邁(mai)出了重要的(de)(de)步。
12. 華中科技大學 Peining Li等人
Nanoscale Guiding of Infrared Light with Hyperbolic Volume and Surface Polaritons in van der Waals Material Ribbons. Adv. Mater..
Figure 4. Thickness dependence of h-BN waveguide modes. a) Schematics of the experiment. b) Near-field amplitude images s3 of h-BN waveguides of same nominal width w = 1 µm and different thicknesses d at ω = 1430 cm?1. c) Wavevector of the waveguide modes as a function of thickness. Symbols indicate experimental wavevectors measured at the edge (triangles) and at the center (circles) of the waveguide. The solid and dashed lines show wavevectors obtained with the full-wave simulations. The dotted red line is a guide to the eye. The inset shows line profiles from 16 nm thick waveguide at edge (gray) and center (blue) as indicated by arrows in (b). d) Schematic comparison of dielectric and hyperbolic volume waveguide modes near cutoff, when the thickness of the waveguide is decreased.
摘要:范德(de)華(vdW)材(cai)(cai)料因其所含有的(de)(de)(de)各種化(hua)(hua)(hua)(hua)(hua)子,成為(wei)了新興的(de)(de)(de)納米(mi)尺度(du)(du)光操縱用(yong)材(cai)(cai)料平臺。憑借(jie)范德(de)華材(cai)(cai)料的(de)(de)(de)層狀結(jie)構(gou),這些化(hua)(hua)(hua)(hua)(hua)子在(zai)薄(bo)(bo)片(pian)當(dang)中(zhong)(zhong)呈雙(shuang)(shuang)曲線(xian)(xian)色(se)散和納米(mi)體制(zhi)(zhi)御(yu)模(mo)式(shi)(shi)。另方(fang)面(mian),它們(men)(men)在(zai)薄(bo)(bo)片(pian)邊緣則呈面(mian)制(zhi)(zhi)御(yu)模(mo)式(shi)(shi)。然而令人意(yi)想不到(dao)的(de)(de)(de)是,這些模(mo)式(shi)(shi)在(zai)以典型(xing)的(de)(de)(de)線(xian)(xian)性波(bo)導(dao)結(jie)構(gou)為(wei)代表的(de)(de)(de)帶(dai)狀材(cai)(cai)料上的(de)(de)(de)導(dao)向正(zheng)全(quan)·方(fang)位地亟待研究。作者(zhe)就六方(fang)氮(dan)化(hua)(hua)(hua)(hua)(hua)硼帶(dai)中(zhong)(zhong)雙(shuang)(shuang)曲聲子化(hua)(hua)(hua)(hua)(hua)子的(de)(de)(de)傳(chuan)播方(fang)式(shi)(shi)的(de)(de)(de)研究成果做了詳細的(de)(de)(de)報告。通(tong)過(guo)納米(mi)紅(hong)外(wai)成像,作者(zhe)觀測到(dao)了各種模(mo)式(shi)(shi)。尤其是展現(xian)出截止寬度(du)(du)的(de)(de)(de)重(zhong)要的(de)(de)(de)體波(bo)導(dao)模(mo)式(shi)(shi)。并且(qie)有趣的(de)(de)(de)是該截止寬度(du)(du)可(ke)以通(tong)過(guo)降低波(bo)導(dao)厚(hou)度(du)(du)來減小。除(chu)此之外(wai),該團隊還(huan)觀察(cha)到(dao)了具(ju)有不同頻(pin)率和波(bo)導(dao)寬度(du)(du)的(de)(de)(de)面(mian)模(mo)式(shi)(shi)雜(za)化(hua)(hua)(hua)(hua)(hua)以及演化(hua)(hua)(hua)(hua)(hua)。而重(zhong)點是,作者(zhe)發現(xian)對稱(cheng)雜(za)化(hua)(hua)(hua)(hua)(hua)面(mian)模(mo)式(shi)(shi)并沒有展現(xian)出任何截止寬度(du)(du),這讓任意(yi)窄帶(dai)里的(de)(de)(de)化(hua)(hua)(hua)(hua)(hua)子都呈線(xian)(xian)性波(bo)導(dao)。另外(wai),研究者(zhe)的(de)(de)(de)實驗數據(ju)也支持了相關的(de)(de)(de)模(mo)擬結(jie)果,這為(wei)我(wo)們(men)(men)在(zai)未來的(de)(de)(de)光子器件應用(yong)中(zhong)(zhong)擔當(dang)重(zhong)任的(de)(de)(de)線(xian)(xian)性波(bo)導(dao)雙(shuang)(shuang)曲化(hua)(hua)(hua)(hua)(hua)子的(de)(de)(de)理解打下了堅實的(de)(de)(de)基礎。
13. 清華大學 Shuai Wu等
Super-Slippery Degraded Black Phosphorus/ Silicon Dioxide Interface. ACS Appl. Mater. Interfaces.
Figure 3. Chemical structure of the BP/SiO2 interface. (a) AFM amplitude image and (b) phase image (scale bars: 2 μm) after the motion of the degraded BP flake on the SiO2 substrate. (c) Normalized nano-FTIR phase (φ) spectroscopy plots of the degraded BP surface, residuals on the substrate, and fresh BP flake (exfoliated within 30 min) in the region of 900–1100 cm–1. (d) {1H-31P}1H double CP spectra of the BP/SiO2 sample; the first contact time (tCP1) was set to 5 ms, and the variable second contact time (tCP2) is indicated on each spectrum.
摘要:二維(2D)材料與二氧化硅(SiO2)/硅(Si)基底之間的界面,通常被看做是固固機械接觸。這在微系統和納米工程的結構設計與性能化時,常常會被別強調。不過,如何理解基于2D材料的系統的界面結構與動力學仍然是個懸而未決又無法繞過的問題。在本研究中,由于在常態降解時引入了羥基,層在界面內可流動的水被插入了降解黑鱗(BP)薄片與SiO2/Si基底之間。因此,作者得到了個滑度*的降解BP/SiO2界面。通過實驗測定,其界面剪切應力(ISS)可低達0.029 ± 0.004 MPa,這數值已可與非公度剛性晶體接觸比肩。通過分析核磁共振波譜儀和原位X射線光電子能譜儀進行的結果,該團隊發現界面內的液態水的存在是剪切應力低的超高滑度BP/SiO2界面的形成主因。這(zhe)發現(xian)證明了降解(jie)BP和(he)水分子之間存在著(zhu)強烈的互相(xiang)影(ying)響,并表明納米BP膜(mo)在生(sheng)物基潤滑域有著(zhu)廣泛的應用潛(qian)力(li)。
14. 北京理工大學 Tao Yan等人
Facile preparation and synergetic energy releasing of nano-Al@RDX@Viton hollow microspheres. Chem. Eng. J..
Figure 4. Topography (a) and near-field amplitude image of the microsphere at frequency ω?=?923?cm?1 (b), 1131?cm?1 (c) and 1168?cm?1 (d). Line profiles of infrared signal extracted at the position indicated by the red dashed line (e).
摘要:為了提高(gao)含能(neng)材料的(de)(de)反(fan)應速(su)率,電噴霧技(ji)術被應用于雙溶劑(ji)法(fa)集成納米(mi)(mi)鋁(nAl)和氟橡膠(Viton)的(de)(de)重結(jie)晶(jing)環三(san)亞甲基三(san)硝胺(an) (RDX)微(wei)球(qiu)(qiu)的(de)(de)開發。其形貌征與化學異質性的(de)(de)測試結(jie)果表明電噴霧生成的(de)(de)微(wei)球(qiu)(qiu)是(shi)空心的(de)(de),并有RDX均(jun)勻地(di)(di)分(fen)布(bu)在其中。而(er)且RDX的(de)(de)納米(mi)(mi)晶(jing)體是(shi)緊密地(di)(di)附著在nAl@Viton骨架的(de)(de)兩側的(de)(de),這增大(da)了不同(tong)組分(fen)之間的(de)(de)接觸面積(ji)。另(ling)方面,對微(wei)球(qiu)(qiu)的(de)(de)熱分(fen)析則表明,通過減小微(wei)球(qiu)(qiu)分(fen)解的(de)(de)表觀活化能(neng),nAl顆粒能(neng)夠加速(su)能(neng)量的(de)(de)釋放。實驗結(jie)果表明電噴霧nAl@RDX@Viton,因其各組分(fen)的(de)(de)征結(jie)構和協(xie)同(tong)作(zuo)用,比物(wu)理混合(he)物(wu)具有更(geng)短的(de)(de)激光(guang)點火延(yan)遲和更(geng)劇(ju)烈的(de)(de)燃燒火焰(yan)。
15. 上海光機所 Lulu Chen等人
Near-field imaging of the multi-resonant mode induced broadband tunable metamaterial Absorber. RSC Adv..
Figure 5. (a) Experimental absorptivity of the GST absorber between two states. The black line and red line are for the a-GST and c-GST sample. (b) The simulated spectra for the total and each layer of the c-GST absorber. Inset: the magnetic field distribution at the resonance wavelength. (c–f) Experimental and simulated near-field amplitude |Ez| and phase φz images mapped at the spectral positions C and C1.
摘要:具有可調性的超材料吸收器在中紅外吸收的應用域具有廣闊的前景。雖然研究者們提出了各種控制吸收的方法,如何深入分析和呈現吸收機制的物理圖像仍是值得期待且有意義的。在本文中,作者用近場光學顯微鏡展示了多諧振模式誘導下的帶寬可調超材料吸收器的實驗空間近場分布。該吸收器由雙倍尺寸的單元結構與金屬鏡片構成,二者由Ge2Sb2Te5 (GST)薄(bo)墊片加以分割(ge)。為(wei)了獲得清晰的物(wu)理圖像(xiang),作者用(yong)由四個方(fang)形諧(xie)振器(qi)組(zu)成的混(hun)合單元(yuan)結構,在 7.8 μm 和 8.3 μm 處(chu)產(chan)(chan)生兩個吸(xi)(xi)收(shou)峰。當GST薄(bo)膜從非晶(jing)態轉(zhuan)變(bian)為(wei)晶(jing)態時,共振的中(zhong)心波長呈現紅移趨勢。而無論GST處(chu)于那種(zhong)相態,我們(men)都分別在其吸(xi)(xi)收(shou)頻(pin)率下觀察到了吸(xi)(xi)收(shou)器(qi)產(chan)(chan)生的近場(chang)振幅和相位(wei)的光(guang)(guang)學信號。綜上,本(ben)研究為(wei)光(guang)(guang)學可調吸(xi)(xi)收(shou)的控(kong)制打下了科學理論的基礎(chu),并(bing)展現了其潛(qian)在的應用(yong)前景。
16. 中國科學技術大學 Wenhao Zhang and Yuhang Chen
Visibility of subsurface nanostructures in scattering-type scanning near-field optical microscopy imaging. Opt. Expr..
Figure 1. (a) Schematic illustration of the experimental s-SNOM setup for investigating the visibility of buried structures in a multilayered architecture. The underneath structures are patterned on a metal film and they are covered with a thin polymer layer. A pseudoheterodyne detection method is employed to obtain background-free near-field optical signal. (b) Schematic illustration of the dipole model for a simple theoretical analysis.
Figure 7. Subsurface nano-imaging by s-SNOM. The sample is a patterned silicon substrate covered by the glue from a double-side tape. (a) Topography. (b) The third harmonic s-SNOM amplitude. The inset is a zoomed view of the area sketched by the dashed rectangle. (c) Sectional profiles of the topography and amplitude images. The two profiles are taken from the same position as guided by the dashed line in topography.
摘要:以納米分辨率探(tan)測被膜材料覆蓋(gai)的(de)(de)結(jie)構(gou)(gou)有(you)著很高的(de)(de)重要性。在(zai)本研究中(zhong),作者用散射型掃描(miao)近(jin)場光學(xue)顯(xian)微鏡(s-SNOM)探(tan)索(suo)了(le)(le)影響(xiang)面下(xia)材料對比度和結(jie)構(gou)(gou)可見度的(de)(de)因素。作者生成(cheng)了(le)(le)種包含不(bu)同掩埋結(jie)構(gou)(gou)的(de)(de)多層(ceng)結(jie)構(gou)(gou)參考(kao)樣品,用來做s-SNOM成(cheng)像。還(huan)研究了(le)(le)近(jin)場光學(xue)對比度對結(jie)構(gou)(gou)幾何形狀、尺寸和覆蓋(gai)層(ceng)厚度的(de)(de)影響(xiang)。結(jie)果(guo)表明區(qu)分掩埋狹縫(feng)圖樣比具有(you)相(xiang)同臨界尺寸的(de)(de)圓孔更容易。s-SNOM能(neng)夠(gou)在(zai)100多納米厚的(de)(de)聚甲基丙(bing)烯(xi)酸甲酯層(ceng)下(xia)感(gan)知材料之間的(de)(de)差異,其(qi)面下(xia)空(kong)間分辨率可以好過100納米。
17. 華中科技大學 Dong Wei等人
Optical modulator based on the coupling effect of different surface plasmon modes excited on the metasurface. Opt. Mater. Expr..
Figure 6. SEM, AFM and near-field lightwave intensity distribution of the NRANC metasurface. (a) SEM images of a metasurface sample, (b) near-field lightwave intensity distribution on the sample, (c) near-field lightwave intensity distribution along red dashed line. The white dashed lines are the outlines of the nano-apertures. The red dotted line is the trendline of the electric intensity distribution curve. (d) AFM image of the metasurface sample.
摘要:作者設計并(bing)生成了種(zhong)由帶中央(yang)納(na)(na)(na)米(mi)(mi)柱的(de)(de)(de)(de)(de)納(na)(na)(na)米(mi)(mi)脊孔陣列(NRANC)構(gou)成的(de)(de)(de)(de)(de)超(chao)(chao)表(biao)(biao)面(mian)光(guang)(guang)學(xue)調制器。研(yan)究(jiu)者還(huan)細致地研(yan)究(jiu)了,分(fen)布在(zai)納(na)(na)(na)米(mi)(mi)脊孔的(de)(de)(de)(de)(de)每個納(na)(na)(na)米(mi)(mi)頂點和(he)(he)中央(yang)納(na)(na)(na)米(mi)(mi)圓柱外(wai)緣上(shang)的(de)(de)(de)(de)(de)局(ju)域表(biao)(biao)面(mian)等離子體(LSPs),與(yu)在(zai)周期性超(chao)(chao)表(biao)(biao)面(mian)上(shang)生成的(de)(de)(de)(de)(de)表(biao)(biao)面(mian)等離子體激(ji)元(SPPs),這二者之(zhi)間(jian)(jian)的(de)(de)(de)(de)(de)耦合(he)效應(ying)。這種(zhong)錐形(xing)結構(gou)可用于入射(she)(she)能量(liang)的(de)(de)(de)(de)(de)集中與(yu)局(ju)部光(guang)(guang)場的(de)(de)(de)(de)(de)增(zeng)(zeng)強(qiang)(qiang)。而(er)在(zai)其上(shang)的(de)(de)(de)(de)(de)感(gan)應(ying)電(dian)偶子則可以(yi)調節(jie)反射(she)(she)或透(tou)射(she)(she)性。這種(zhong)在(zai)NRANC 上(shang)形(xing)成的(de)(de)(de)(de)(de)LSPs的(de)(de)(de)(de)(de)耦合(he)效應(ying)將(jiang)增(zeng)(zeng)強(qiang)(qiang)表(biao)(biao)面(mian)感(gan)應(ying)電(dian)偶子,并(bing)進步(bu)調節(jie)NRANC的(de)(de)(de)(de)(de)光(guang)(guang)學(xue)性。通過改變超(chao)(chao)表(biao)(biao)面(mian)的(de)(de)(de)(de)(de)幾何參數,可以(yi)調整LSPs模式的(de)(de)(de)(de)(de)諧振(zhen)頻(pin)率(lv),并(bing)觀(guan)察到透(tou)射(she)(she)峰的(de)(de)(de)(de)(de)平移,以(yi)及讓增(zeng)(zeng)強(qiang)(qiang)因(yin)數達(da)到1.4×103。另(ling)方面(mian),LSPs和(he)(he)SPPs之(zhi)間(jian)(jian)的(de)(de)(de)(de)(de)耦合(he)則會激(ji)發法諾(nuo)共振(zhen)。在(zai)可見光(guang)(guang)和(he)(he)紅外(wai)范圍內調整照射(she)(she)激(ji)光(guang)(guang)的(de)(de)(de)(de)(de)入射(she)(she)角則能調節(jie)SPPs的(de)(de)(de)(de)(de)激(ji)發,并(bing)因(yin)此引起相對較大的(de)(de)(de)(de)(de)透(tou)射(she)(she)光(guang)(guang)譜變化。于是通過進行近(jin)場光(guang)(guang)學(xue)測量(liang),可以(yi)觀(guan)察到包括表(biao)(biao)面(mian)感(gan)應(ying)電(dian)荷信息在(zai)內的(de)(de)(de)(de)(de)近(jin)場光(guang)(guang)學(xue)性,以(yi)及在(zai)45°入射(she)(she)的(de)(de)(de)(de)(de)633納(na)(na)(na)米(mi)(mi)TM激(ji)光(guang)(guang)照射(she)(she)下的(de)(de)(de)(de)(de)個小(x方向(xiang)上(shang),約96納(na)(na)(na)米(mi)(mi))且亮的(de)(de)(de)(de)(de)熱點。綜(zong)上(shang),作者研(yan)究(jiu)中構(gou)建(jian)的(de)(de)(de)(de)(de)NRANC超(chao)(chao)表(biao)(biao)面(mian)突出(chu)了其在(zai)類似彩色(se)濾(lv)光(guang)(guang)片、反射(she)(she)鏡(jing)、表(biao)(biao)面(mian)增(zeng)(zeng)強(qiang)(qiang)拉曼等方面(mian)的(de)(de)(de)(de)(de)潛在(zai)應(ying)用前景。
相關產品:
1、納米傅里葉(xie)紅(hong)外(wai)光譜儀-Nano-FTIR
2、超(chao)高分辨散射(she)式近場光學顯微(wei)鏡-neaSNOM