APL Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

6 Sep 2004

Volume 85, Issue 10, pp. 1659-1861

Issue Cover Spotlight Figure

Appl. Phys. Lett. 85, 1793 (2004); http://dx.doi.org/10.1063/1.1790588 (3 pages)

Hyunsik Yoon, Kyoung Mi Lee, Dahl-Young Khang, Hong H. Lee, and Se-Jin Choi
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

Laser threshold reduction in an all-spiro guest–host system

D. Schneider, T. Rabe, T. Riedl, T. Dobbertin, M. Kröger, E. Becker, H.-H. Johannes, W. Kowalsky, T. Weimann, J. Wang, and P. Hinze

Appl. Phys. Lett. 85, 1659 (2004); http://dx.doi.org/10.1063/1.1792794 (3 pages) | Cited 22 times

Online Publication Date: 13 September 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on stimulated emission in an all-spiro guest–host (G–H) system. Different doping concentrations of the guest molecule 2,2′,7,7′-tetrakis(2,2-diphenylvinyl)spiro-9,9′-bifluorene in the host material 2,7-bis(biphenyl-4-yl)-2′, 7′-di-tert-butyl-9,9′-spirobifluorene were investigated for amplified spontaneous emission (ASE) and distributed feedback (DFB) lasing. The ASE maximum could be shifted over 20 nm by variation of the doping concentration. DFB lasing is observed in the pure host, the pure guest material, and in the G–H system. The laser wavelength can be tuned from 401.5 to 529.3 nm by changing the grating period of the Bragg reflector and the doping concentration. A minimum threshold energy density of 6 μJ∕cm2 was observed in second-order DFB structures for a doping concentration of 1.1%. In first-order DFB operation the threshold value could be further lowered to 320 nJ∕cm2. These results render this material system an excellent candidate for stable and widely tunable lasers in the visible spectrum.
Show PACS
42.55.Rz Doped-insulator lasers and other solid state lasers
42.70.Hj Laser materials

Replica-molded electro-optic polymer Mach–Zehnder modulator

George T. Paloczi, Yanyi Huang, Amnon Yariv, Jingdong Luo, and Alex K.-Y. Jen

Appl. Phys. Lett. 85, 1662 (2004); http://dx.doi.org/10.1063/1.1787944 (3 pages) | Cited 27 times

Online Publication Date: 13 September 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A Mach–Zehnder electro-optic polymer amplitude modulator is fabricated by a simple and high-throughput soft-stamp replica-molding technique. The modulator structure incorporates the highly nonlinear and stable chromophore, AJL8, doped in amorphous polycarbonate. Single-arm phase-retardation results in a halfwave voltage (Vπ) of 8.4 V at 1600 nm. The on/off extinction ratio is better than 19 dB, resulting from precise Y-branch power splitters and good waveguide uniformity. These results indicate that the simple fabrication process allows for good optical performance from high-fidelity replicas of the original master devices.
Show PACS
07.60.Ly Interferometers
42.82.Cr Fabrication techniques; lithography, pattern transfer
42.70.Jk Polymers and organics
81.10.Fq Growth from melts; zone melting and refining
42.65.Wi Nonlinear waveguides

Photodimerization in dipeptides for high capacity optical digital storage

P. S. Ramanujam and Rolf H. Berg

Appl. Phys. Lett. 85, 1665 (2004); http://dx.doi.org/10.1063/1.1787948 (3 pages) | Cited 7 times

Online Publication Date: 13 September 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have developed peptide materials with chromophores that undergo cycloaddition, suitable for terabit optical digital storage in a 5.25 in. disc. The rationale behind this design is that the length and rigidity of the backbone can be adjusted to facilitate the formation of a photodimer without large physical movements of the chromophores on exposure to UV light. Initially strongly absorbing films transmit up to 50% of light on irradiation at dimerizing wavelengths. This property can be utilized to record grey levels. An intensity-dependent transmission behavior has been observed that may enable data to be written and read at the same wavelength.
Show PACS
82.30.Nr Association, addition, insertion, cluster formation
78.66.Qn Polymers; organic compounds
61.82.Pv Polymers, organic compounds
42.70.Jk Polymers and organics
78.40.Me Organic compounds and polymers
61.80.Ba Ultraviolet, visible, and infrared radiation effects (including laser radiation)
82.50.-m Photochemistry
42.79.Vb Optical storage systems, optical disks

InGaAs-on-Si single photon avalanche photodetectors

Y. Kang, Y.-H. Lo, M. Bitter, S. Kristjansson, Z. Pan, and A. Pauchard

Appl. Phys. Lett. 85, 1668 (2004); http://dx.doi.org/10.1063/1.1788882 (3 pages) | Cited 8 times

Online Publication Date: 13 September 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In this letter, an InGaAs-on-Si single photon avalanche diode (SPAD) for telecommunication wavelengths is presented. This SPAD demonstrates high-single-photon quantum efficiency and low-dark-count probability under gated mode operation. We attributed the good performance of this device to the high absorption coefficient of InGaAs and low noise avalanche multiplication of Si.
Show PACS
85.60.Gz Photodetectors (including infrared and CCD detectors)
85.60.Dw Photodiodes; phototransistors; photoresistors
72.40.+w Photoconduction and photovoltaic effects
85.30.Kk Junction diodes
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)

Zero voltage Freedericksz transition in periodically aligned liquid crystals

James N. Eakin, Yunhe Xie, Robert A. Pelcovits, Marc D. Radcliffe, and Gregory P. Crawford

Appl. Phys. Lett. 85, 1671 (2004); http://dx.doi.org/10.1063/1.1789578 (3 pages) | Cited 38 times

Online Publication Date: 13 September 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Patterned alignment layers have been created through an approach using polarization holography and a photopolymerizable alignment layer. This technique enables continuously periodic boundary conditions on planar surfaces. Polarization gratings have been created using polarization interference from incident right-handed and left-handed circular polarization exposure conditions. A simple phenomenological model is derived to show that the Freedericksz threshold voltage vanishes when the cell gap and grating pitch are comparable.
Show PACS
42.40.Eq Holographic optical elements; holographic gratings
64.70.M- Transitions in liquid crystals
42.79.Dj Gratings
42.70.Jk Polymers and organics
42.25.Hz Interference
42.70.Df Liquid crystals
61.30.Vx Polymer liquid crystals

2.9 THz quantum cascade lasers operating up to 70 K in continuous wave

S. Barbieri, J. Alton, H. E. Beere, J. Fowler, E. H. Linfield, and D. A. Ritchie

Appl. Phys. Lett. 85, 1674 (2004); http://dx.doi.org/10.1063/1.1784874 (3 pages) | Cited 79 times

Online Publication Date: 13 September 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report the operation of a quantum cascade laser emitting at a 103 μm wavelength (2.9 THz). The active region is based on a bound-to-continuum design allowing a low parasitic leakage current, and a high upper-to-lower-state lifetime ratio. The latter is demonstrated by a pronounced decrease of the differential resistance at threshold, which is visible up to high temperatures, and by a weak temperature dependence of the slope efficiency. At 4 K, we report a threshold current density of only 105 A∕cm2 both in pulsed and continuous-wave operation, and an emitted peak power of 15 mW independent of the duty cycle. Maximum operating temperatures of 95 K and 70 K are observed in pulsed and continuous wave modes, respectively.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.60.By Design of specific laser systems
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close