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41.
Morton P.A. Tanbun-Ek T. Logan R.A. Chand N. Wecht K.W. Sergent A.M. Sciortino P.F. Jr. 《Electronics letters》1994,30(24):2044-2046
25 GHz modulation bandwidth is achieved from a fully packaged 1.55 μm DFB laser, using devices with p-doped compressively strained MQW active regions and large negative wavelength detuning. Devices on submounts show a record bandwidth of 26 GHz, limited by device and bonding parasitics. Resonance frequencies of over 26 GHz are measured 相似文献
42.
We derive a master equation for a mirror interacting with the vacuum field via radiation pressure. The dynamical Casimir effect leads to decoherence of a superposition state in a time scale that depends on the degree of "macroscopicity" of the state components, and which may be much shorter than the relaxation time scale. Coherent states are selected by the interaction as pointer states. 相似文献
43.
44.
We report on the tunable dual-mode operation of a chirped grating distributed-feedback (DFB) laser device with two integrated modulators which act as tuning sections. A transfer-matrix model is used to simulate the amplified spontaneous emission spectrum for a chirped grating DFB laser. Several types of dual-mode operation are observed for wavelength spacings of 0.5 nm and 1.4 nm corresponding to frequency detunings of 63 GHz and 175 GHz 相似文献
45.
Tanbun-Ek T. Andrekson P.A. Logan R.A. Chu S.N.G. Coblentz D.L. Sergent A.M. Wecht K.W. 《Photonics Technology Letters, IEEE》1992,4(7):685-688
Novel MQW integrated passive waveguide (IPW) DFB lasers have been fabricated using a selective area MOVPE growth technique. Detailed measurements of the absorption loss of the passive waveguide in the structure as well as its influences on the laser linewidth are reported for the first time. A linewidth reduction factor of more than 3 is observed as compared to a simple DFB laser despite the high absorption loss 相似文献
46.
Zhijun Liu D. Wasserman S.S. Howard A.J. Hoffman C.F. Gmachl Xiaojun Wang T. Tanbun-Ek Liwei Cheng Fow-Sen Choa 《Photonics Technology Letters, IEEE》2006,18(12):1347-1349
We report on room-temperature continuous-wave (CW) operation of /spl lambda//spl sim/8.2 /spl mu/m quantum cascade lasers grown by metal-organic chemical vapor deposition without lateral regrowth. The lasers have been processed as double-channel ridge waveguides with thick electroplated gold. CW output power of 5.3 mW is measured at 300 K with a threshold current density of 2.63 kA/cm/sup 2/. The measured gain at room temperature is close to the theoretical design, which enables the lasers to overcome the relatively high waveguide loss. 相似文献
47.
T. Tanbun-Ek N.A. Olsson R.A. Logan K.W. Wecht A.M. Sergent 《Photonics Technology Letters, IEEE》1991,3(2):103-105
The polarization-dependent gain spectra of both tensile and compressive strain multiple-quantum-well (MQW) In/sub x/Ga/sub 1-x/As-InP lasers in a relatively large strain regime are presented. The results show that MQW lasers with tensile strain and an In concentration as low as 43% in the wells lase in a pure transverse magnetic (TM) mode rather than a transverse electric (TE) mode with a gain difference of 60-70 cm/sup -1/ at all the injection currents investigated. The peak gain for the TE mode is shifted toward shorter wavelengths from that of the TM mode, indicating that the emission is principally due to light hole-electron transition. The differential gain of the TM mode is about 1.5 times higher than that of the TE mode operation. Opposite phenomena were observed in the compressive strained MQW lasers.<> 相似文献
48.
Olsson N.A. Andrekson P.A. Becker P.C. Simpson J.R. Tanbun-Ek T. Logan R.A. Presby H. Wecht K. 《Photonics Technology Letters, IEEE》1990,2(5):358-359
The use of semiconductor-laser-pumped erbium-doped fiber amplifiers and an externally modulated mode-locked external-cavity semiconductor laser to obtain soliton data transmission at 4 Gb/s over 136 km of nondispersion shifted fiber is described. After 136 km of transmission and at low pulse powers, the ~80 ps fiber input pulse width was broadened to ~150 ps. At high pulse powers the output pulse width was maintained at 80 ps, as expected for N =1 solitons. N =3 solitons were also observed at lower data rates 相似文献
49.
50.
Morton P.A. Mizrahi V. Andrekson P.A. Tanbun-Ek T. Logan R.A. Lemaire P. Coblentz D.L. Sergent A.M. Wecht K.W. Sciortino P.F. Jr. 《Photonics Technology Letters, IEEE》1993,5(1):28-31
The authors report a mode-locked pulse source with extremely wide operating frequency range and very stable operation, through the use of a long, linearly chirped Bragg reflector as the output coupler integrated in a fiber external cavity. A 1.55 μm strained MQW laser diode is used, with one facet high reflectivity (HR) coated for improved cavity Q , and the other antireflection (AR) coated to allow coupling to the external cavity and suppress Fabry-Perot modes. Near-transform-limited pulses are obtained over a frequency range of 700 MHz around a system operating frequency of 2.488 GHz, with pulsewidths of 50 ps, as required for a practical soliton transmission system 相似文献