摘要:

Semitransparent thin silver films are employed as both the top mirrors and electrodes for GaAs vertical‐cavity surface‐emitting lasers. The semitransparent silver films allow the emission of light from the top epitaxial side. Quarter‐wave AlAs/AlxGa1−xAs stacks are used as the bottomn‐type mirrors. Light output versus excitation current measurements yields an efficiency of 0.76 mW/mA from the top silver mirror side, which corresponds to an external differential quantum efficiency of 54% at a lasing wavelength of 0.88 &mgr;m. The internal differential quantum efficiency is estimated to be ≳94%. An optical output power of 10 mW is obtained at a pulsed excitation current of 72 mA.

ISSN:0003-6951    

DOI:10.1063/1.103936

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

We report on high‐power AlGaAs/GaAs graded‐index single quantum well surface‐emitting lasers (SELs), with etched vertical mirrors and integrated 45° beam deflectors fabricated by a tilted ion beam etching technique. 100‐&mgr;m‐wide, 500‐&mgr;m‐long, broad‐area SELs exhibited a threshold current of 300 mA, a peak power of more than 380 mW, and an external differential quantum efficiency of 17% without facet coating. The SELs showed stable operation up to 7th. These results show the highest power and external differential quantum efficiency reported to date for 45° beam deflecting SELs. The full widths at half maximum of the surface‐emitting far‐field pattern parallel and perpendicular to the laser axis were 8.5° and 14°, respectively.

ISSN:0003-6951    

DOI:10.1063/1.103937

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

We have intermixed GaAs/(AlGa)As multiquantum structures for waveguides and lasers by 3 MeV Ar implantation and 850 °C, 30 min closed‐tube annealing. Buried‐heterostructure lasers defined by Ar mixing had threshold currents of 100 mA for 370‐&mgr;m‐long devices. As waveguides for 1.15 &mgr;m light, the devices exhibited losses of 25 cm−1in the annealed, implanted regions, and 15 cm−1in unimplanted regions defined by adjacent implants. Analysis of the results illustrates important considerations for implant mixing for waveguide formation.

ISSN:0003-6951    

DOI:10.1063/1.104115

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Monolithically integrated master oscillator/power amplifiers have been fabricated with a single‐mode distributed Bragg reflector laser as the oscillator and a chain of amplifier output couplers defined by a single‐mode waveguide gain region and a second‐order grating detuned from the gain peak. The output of the amplifier chain is a single frequency and can be phased to obtain a diffraction‐limited output up to an output power of 485 mW.

ISSN:0003-6951    

DOI:10.1063/1.103938

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

A quasi‐continuous KrF(248 nm:B→X)fluorescence of over 8 ms pulse duration with a 100 Hz operation frequency was observed in a microwave‐discharge‐pumped KrF lamp with an Ar buffer gas in place of the He/Ne buffer. With an average microwave power deposition of 517.1 W, the maximum average KrF fluorescence power was 58.2 W obtained at a KrF intrinsic efficiency of 11.2% with the lamp gas mixture of F2/Kr/Ar=4/2/94(%) at 50 Torr and simultaneously an average ArF(193 nm:B→X) fluorescence power of 17.4 W with over 8 ms pulse duration at a 100 Hz operation frequency was also obtained. Based on the total fluorescence power of ArF and KrF, the intrinsic efficiency becomes as high as 14.6%. The maximum KrF intrinsic efficiency was 13.8% obtained with a lamp gas mixture of F2/Kr/Ar=2/2/96(%) at 50 Torr. The maximum average KrF fluorescence power and KrF intrinsic efficiency with the Ar buffer has exceeded the maximum average KrF fluorescence of 53 W and the corresponding KrF intrinsic efficiency of 8.3% achieved previously with the lamp gas mixture of F2/Kr/He/Ne=2/1/48.5/48.5(%) at 50 Torr. Dual wavelength emission should be useful for those that need both the 248 and 193 nm wavelengths.

ISSN:0003-6951    

DOI:10.1063/1.103939

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

An optical analogue of a voltage‐controlled oscillator based on an optical resonant amplifier structure is proposed and experimentally demonstrated. By using tunable distributed Bragg reflector and distributed feedback laser diode amplifiers, we demonstrate oscillators with frequencies controllable from several hundred MHz into multiGHz range. Such devices may find applications in future all‐optical signal processing and optical communication systems.

ISSN:0003-6951    

DOI:10.1063/1.103940

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The dispersion of a parameter quantifying the effects of two‐photon absorption on all‐optical waveguide switching devices is evaluated for the case of semiconductors in a two band model. Serious limitations are predicted based on the nonresonant bound electron response for photon energies between the band gap and one half the band gap.

ISSN:0003-6951    

DOI:10.1063/1.103941

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

We have demonstrated the first successful preparation of InGaAs/InGaAsP multiple quantum well (MQW) lasers grown by chemical beam epitaxy. The broad‐area threshold current densities of standard (not graded index) separate confinement heterostructure (SCH) MQW lasers were as low as 860 and ∼590 A/cm2for cavity lengths of 500 and 1500–3500 &mgr;m. Such values are similar to those obtained from MQW wafers employing the more advanced graded index SCH(GRIN‐SCH) grown by metalorganic vapor phase epitaxy. Buried‐heterostructure lasers also have similar threshold currents, i.e., 25–40 mA for 300–1500 long cavities. Pulsed and cw output power at 1.57 &mgr;m as high as 216 and 140 mW were obtained from 1‐mm‐long buried‐heterostructure lasers having antireflection and high reflection coatings of ∼5% and ∼85%. The layer thickness uniformity is better than ±1% across a 2‐in.‐diam wafer.

ISSN:0003-6951    

DOI:10.1063/1.103942

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The ‘‘gain lever’’ effect in two‐section single quantum well lasers can be used in enhancing the frequency modulation (FM) efficiency of the laser without a corresponding increase in the FM noise, i.e., linewidth. Theoretical and experimental results of the FM efficiency, speed, tuning range, and linewidth will be discussed and compared to other tunable laser structures.

ISSN:0003-6951    

DOI:10.1063/1.103943

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

One‐to‐30 guided wave optical interconnections are demonstrated at 632.8 nm using a highly multiplexed waveguide volume hologram. This technology is capable of providing intrachip and intrawafer optical interconnections. The theoretical limit of the fanout number is addressed and experimentally confirmed. The measured data show that the diffracted beams have an average diffraction efficiency of 2.3% with ±0.2% variation. The demonstrated results can save surface space of electronic chips and also provide a large fanout capability due to the high index modulation of the volume hologram. Further applications based on this technology are very promising. Head‐up display, high‐speed optical data bus, surface enhanced Raman spectrometer, and optical sensors are some of the attractive ones.

ISSN:0003-6951    

DOI:10.1063/1.103944

出版商:AIP    

年代:1990

数据来源: AIP