摘要:

We present the case of photoionization-induced holeburning in rare-earth-doped II–VI compounds for high-density persistent holeburning. In this case, the photoproduct of holeburning is distributed across the entire zero-phonon line. This maximizes the total number of possible spectral holes that can be burned into an inhomogeneous line as well as produces holes that are photoerasable. Experimental data on photon-gated holeburning inMgS:Eu2+,Eu3+are presented. With the proper choice of the host electronic band structure, the optically active rare-earth ion and its electronic transitions involved in the holeburning process, to the best of our knowledge we have observed the highest number of photon-gated holes ever burned in a single electronic transition. The features of these holes are that they suffer no detectable erasure after several thousands of read cycles, they survive thermal cycling to ∼150 K, and they are completely photoerasable. A special case of photon-gated holeburning, power-gated holeburning, was employed to demonstrate that, in such systems, a single laser can be used for burning, reading, and erasing of the spectral holes. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.121677

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

A mode-locked and gain-switched photolytic iodine laser Zeeman tuned to operate simultaneously on the two strongest hyperfine transitions is shown to emit 1.315 &mgr;m radiation modulated at 13.9 GHz. The interaction of this laser radiation with suitable targets leads to the generation of microwave pulses that consist of only a few cycles at 13.9 GHz, making the system attractive for ultra-wide-band, short pulse radar applications. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.121646

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

An all-optically induced spatial shift in the interference between the two lowest-order modes of a lithium niobate channel waveguide was demonstrated based on the power-dependent nonlinear phase shift induced via quadratic cascading. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.121647

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

The Si/Si oxynitride superlattices, with three periods, have been grown using the two-target alternation magnetron sputtering technique. The thicknesses of Si oxynitride layers and Si layers in the superlattices are 2.0 and 1.4 nm, respectively. Visible electroluminescence (EL) from a semitransparent Au film/(Si/Si oxynitride) superlattice/p-Si structure has been observed. Each EL spectrum of the structure has a dominant peak around 640 nm, a weaker peak around 520 nm, and a shoulder around 820 nm. By comparing the EL from the semitransparent Au film/(Si/Si oxynitride) superlattice/p-Si structure with that from a semitransparent Au film/Si oxynitride film/p-Si structure, we found that the EL efficiency of the former structure is about 2–4 times of that of the latter one. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.121648

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

Data are presented demonstrating 300 K, continuous wave (cw) photoluminescence near&lgr;=1.53 &mgr;mfrom Er-implantedAl0.8Ga0.2Asfilms oxidized in water vapor (N2+H2O,500 °C) and annealed (1 h,700 °C) inAr+O2.The 40 nm full width at half-maximum (FWHM) spectra are1.5×broader and∼10×more intense relative to spectra from unoxidized but annealed samples. The fluorescence decay shows a&tgr;=7 mslifetime, with a faster&tgr;=1.9 mscomponent characteristic of a cooperative upconversion mechanism. The data suggest thatAlxGa1−xAsnative oxides may provide a suitable host for rare-earth optical activity. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.121649

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

This letter reports exceptionally broadband tuning of a continuous-wave optical parametric oscillator (cw OPO) using a temperature tuned, nonlinear crystal ofMgO:LiNbO3pumped by a diode-pumped, intracavity doubled Nd:YAG laser. The tuning range from 788 to 1640 nm, is about four times broader than those ever reported in cw OPOs operating around 1 &mgr;m. This performance was accomplished by newly developed, extremely broadband, high-reflection mirrors for the doubly resonant oscillation, designed to have a reflectivity of 99&percent; from 0.7 to 1.6 &mgr;m. Threshold pump power increased from 80 mW near degeneracy to 150 mW at the tuning band edge in a double pass pumping configuration. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.121650

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

Faraday rotation of the polarization for a 1550 nm probe beam induced by a pump beam at shorter wavelength is studied inHg1−xMnxTesemimagnetic semiconductors. Photoinduced rotation decays in a nanosecond timescale and it is related to carrier-induced refractive index saturation. Observed decay is discussed in terms of photoexcited carrier dynamics. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.121651

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

An electric pulsed-poling technique is developed for achieving high-performance electro-optic polymers. A high poling field of 1 kV/&mgr;m can be applied across a polymer thin film without experiencing breakdown. This poling technique has been applied to a guest-host nonlinear polymeric system of photolime gel and chlorophenol red with loading concentration of 30 wt &percent;. An electro-optic coefficient up to 40 pm/V at the 632.8 nm wavelength is achieved, which is 35&percent; higher than that obtained by using conventional poling approaches. After decay the electro-optic coefficient can be fully recovered using the same poling method at room temperature. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.121652

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

Readout signal, noise, and cross-track cross talk were investigated for edge detection in a phase-change optical data storage system. Both theoretical and experimental results indicate that edge detection has a performance superior to the conventional detection of reflectance variations, especially when the amorphous marks are shorter than the size of the focused spot. More than 50 dB of carrier to noise ratio for marks of 0.36 &mgr;m in length is obtained using light at a wavelength of 690 nm and an objective lens of 0.6 numerical aperture. Diffraction analysis on the cross talk has shown that, in the scheme of land-groove recording, there is no optimum groove depth which can cancel the cross talk from adjacent tracks. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.121653

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

We show how a structural element introduced into a vertical cavity surface emitting laser (VCSEL) results in the device operating in single stable high-order mode. The results from a 55 &mgr;m diameter device,&lgr;=772 nm,are presented. The stability of the mode structure is investigated as a function of injection current. A simple theory, based on a modal loss discrimination mechanism in VCSELs with slightly perturbed mirrors, is used to explain the preferred lasing mode in VCSEL structures using a central etched well. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.121654

出版商:AIP    

年代:1998

数据来源: AIP