摘要:

Frequency conversion of two laser diodes in a proton‐exchanged MgO‐doped LiNbO3waveguide is reported. Simultaneous generation of blue (0.43 &mgr;m), green (0.52 &mgr;m), and red (0.65 &mgr;m) coherent radiation by sum‐frequency and second‐harmonic generation of laser diodes at wavelengths of 0.86 and 1.3 &mgr;m has been observed for the first time. This is made possible by the wide phase‐matching bandwidth of the Cherenkov radiation scheme.

ISSN:0003-6951    

DOI:10.1063/1.104370

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

We propose to use silver‐covered optical diffraction gratings as possible laser‐driven electron sources. Such structures allow surface plasma waves excitation and consequently an enhancement of the photoemission sensitivity. The latter can easily be tuned with the wavelength of the excitation laser by varying the incidence angle. Using a commercial diffraction grating, we obtained after a cesium activation, a quantum yield higher than 1% at the wavelength of a frequency tripled YAG laser (&lgr;=355 nm) for the incidence angle corresponding to the plasmon resonance.

ISSN:0003-6951    

DOI:10.1063/1.104371

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

Phase‐matched second‐harmonic generation is reported in periodically poled optical fibers for the first time. A periodic &khgr;(2)was induced in optical fibers during phase‐matched periodic‐electric field‐induced second‐harmonic generation at a fundamental wavelength of 1064 nm. Further, it is shown that periodic poling can be achieved by photo excitation with radiation of 514.5 nm wavelength while applying a spatially periodic static field. In both cases, the mode interaction HE&ohgr;11→HE2&ohgr;11is quasi‐phase matched at 1064 nm. Seeding is observed in fibers beyond the poled region. A photoinduced index change has been measured using electric field induced second‐harmonic generation.

ISSN:0003-6951    

DOI:10.1063/1.104372

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

Short optical pulse generation from an external‐cavity laser diode (LD) by optical pulse pumping has been investigated for the first time. An optical pulse train (pulse duration ∼40 ps) generated by a gain‐switched LD was injected into a LD with an external cavity (slave LD) which was biased just below the laser threshold. The wavelength of the injected optical pulse was chosen to be slightly shorter than that of the slave LD. When the repetition rate of the optical injection pulse was nearly equal to the round trip time of the external cavity, the slave LD showed stable mode locking with the shorter pulse duration (∼22 ps) than that of the pumping pulse. At both the upper and lower repetition rates, the pulse duration of the slave LD also became shorter than that of the pumping pulse.

ISSN:0003-6951    

DOI:10.1063/1.104321

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

We describe a photonic integrated circuit composed of a distributed Bragg reflector laser and a fast monitoring photodiode operating at 1.54 &mgr;m wavelength. The integrated waveguide photodiode has a 3 dB bandwidth of 2 GHz with 1.2 mA/mW responsivity. We demonstrate ‘‘on chip’’ monitoring of a digitally modulated laser signal at 2 Gbit/s.

ISSN:0003-6951    

DOI:10.1063/1.104322

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

We measured third‐order, nonlinear optical susceptibility &khgr;(3)for a series of tetrabenzporphyrins in solution in tetrahydrofuran at 532 nm using degenerate four‐wave mixing with picosecond pulses and obtained values of molecular second hyperpolarizability ⟨&ggr;⟩. The corresponding macroscopic &khgr;(3)values calculated for nine compounds with different substituent groups are four to five orders larger than CS2. For five of the compounds the &khgr;(3)values are in the range 1.2–2.8×10−8esu. Our experiments indicate that the nonlinearity is predominately electronic in origin with a response time faster than the 15 ps resolution of our system.

ISSN:0003-6951    

DOI:10.1063/1.104323

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

The intensity noise of strained InxGa1−xAs/InP multiple quantum well (MQW) lasers is measured for three types of strain: tensile strain (x=0.48), no strain (x=0.53), and compressive strain (x=0.65). From a comparison between the measured noise power spectral density and the theoretical one, the resonance frequency and the carrier damping factor of each type of lasers are calculated. Although compressive strained MQW lasers show abot 10% increase in resonance frequency compared to those of tensile strained and unstrained lasers, this increase is smaller than theoretically predicted. Most important, all three types of MQW lasers show about two to three times higher nonlinear gain saturation and lower maximum bandwidth than conventional double‐heterostructure lasers. A solution to reduce this high damping is also discussed.

ISSN:0003-6951    

DOI:10.1063/1.104324

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

We investigated the effect of high operating voltage and series resistance on the dynamic behavior of strained InGaAs/GaAs quantum well vertical‐cavity surface‐emitting lasers (VCSELs). A large wavelength chirp in the lasing spectrum is observed for the lasers with high voltage/resistance even under low‐duty‐cycle pulse operation due to resistive heating close to the laser junction. Using an optimized laser design, VCSELs with 2.6 V threshold voltage and 40 &OHgr; resistance are achieved. We believe this is the lowest threshold voltage and resistance reported to date for a 20 &mgr;m VCSEL with as‐grown mirrors. The wavelength chirp is reduced by nearly two orders of magnitude for these improved lasers.

ISSN:0003-6951    

DOI:10.1063/1.104325

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

We demonstrate the first surface‐emitting laser operation in a vertical‐to‐surface transmission electrophotonic device with a vertical cavity. The thyristor‐like current‐voltage characteristics, which are required for optical and electrical switching, are achieved. Threshold current during the on state is as low as 1.2 mA. All 100 devices, which were randomly extracted from a grown wafer, emit laser light.

ISSN:0003-6951    

DOI:10.1063/1.104326

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

Ultrafast subpicosecond optical pulse generation is achieved by passive colliding‐pulse mode locking of monolithic multiple quantum well InGaAsP semiconductor lasers. Transform‐limited optical pulses with durations of 1.1, 0.83, 1.0, and 0.64 ps are achieved at repetition rates of 40, 80, 160, and 350 GHz, respectively, without using any external ac sources.

ISSN:0003-6951    

DOI:10.1063/1.104327

出版商:AIP    

年代:1991

数据来源: AIP