Coherent light generators – Particular active media – Semiconductor
Patent
1990-06-21
1991-12-03
Epps, Georgia
Coherent light generators
Particular active media
Semiconductor
372 92, H01S 319
Patent
active
050705113
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The invention is directed to a laser arrangement having at least one laser resonator and a passive resonator coupled thereto.
Semiconductor laser arrangements that oscillate in only one mode are known from the literature (see, for example, B. R. Plastow et al, 9th IEEE ISLC, Rio de Janeiro, Aug. 1984, pages 72 ff; Z. L. Liau et al, Appl. Phys. Lett. 46 (1985), pages 115 ff; M. Ohshima et al, 9th IEEE ISLC. Rio de Janeiro, Aug. 1984, pages 188 ff; H. K. Choi et al, Elec. Lett. 19 (1983) pages 302 ff; L. A. Coldren et al, Appl. Phys. Lett. 46 (1985) pages 5 ff). These arrangements contain a plurality of laser-active and laser-passive Fabry-Perot resonators that are longitudinally coupled. The various arrangements differ in terms of their coupling elements. In "cleaved coupled cavity" lasers and "groove-coupled cavity" lasers, an air gap having plane-parallel mirror surfaces is employed as coupling element between two active laser resonators having differing optical length (see, for example, L. A. Coldren et al, Appl. Phys. Lett. Volume 46 (1985), pages 5 ff). In the "active-passive interference" laser, a passive resonator is longitudinally coupled to an active laser resonator via a step in a wave guide structure (see, for example, H. K. Choi and S. Wang, Elec. Lett. Volume 19 (1983) pages 302 ff). In the "internal reflection interference" laser, the coupling ensues via a disturbance of the refractive index that is built into the wave guide (M. Oshima et al, 9th IEEE ISLC, Rio de Janeiro, Aug. 1984, pages 188 ff).
These coupling elements lead to a pronounced and frequency-dependent coupling. Excessive couplings lead to a de stabilization of the operating point of the laser. Great frequency dependency of the coupling leads thereto that abrupt discontinuities of the resonant frequency occur given slight temperature or, respectively, current fluctuations.
SUMMARY OF THE INVENTION
The object of the invention is to specify a further one-mode laser arrangement.
This object is inventively achieved as recited in claim 1. Since multiple reflections between the laser resonator and the passive resonator are present proceeding from the structure, the coupling factor of the arrangement is only slightly dependent on the frequency. This laser arrangement therefore has an improved frequency stability in comparison to the prior art.
The laser arrangement of FIG. 1 has the advantage that the laser resonator and the passive resonator are contained monolithically integrated in a semiconductor layer structure. The adjustment is thereby considerably simplified. The weak coupling required for an optimum frequency stability of the laser arrangement can be reproducibly set in this arrangement on the basis of the angle of inclination of the oblique side wall and on the basis of the width of the trench. Since the passive resonator extends form the vertical side wall of the etched trench up to the end face of the semiconductor layer structure that is situated at the side of the etched trench facing away from the vertical side wall, allowances in the trench width caused by the manufacturing process are not noticed in the operation of the laser arrangement.
The laser arrangement also has the advantage that an attenuation of the laser emission due to optical coupling in transversal direction between the laser-active layer and the transparent wave guide layer is avoided.
As passive resonator, the laser arrangement of FIG. 2 comprises a two-dimensional dielectric disk resonator. Such a disk resonator has a significantly higher quality than a stripe-shaped resonator given identical length.
The laser arrangement of FIGS. 3 and 4 makes it possible to obtain both a longitudinally as well as a laterally one-mode resonant condition.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments of the invention shall be set forth in greater detail below with reference to the figures.
FIG. 1 shows a section through a laser arrangement.
FIG. 2 shows the plan view of the laser arrangement.
FIG. 3 shows an arrangement that
REFERENCES:
patent: 3747020 (1973-07-01), Wieder
patent: 4653058 (1987-03-01), Akiba et al.
patent: 4674096 (1987-06-01), Salzman et al.
patent: 4773077 (1988-09-01), Yamamoto et al.
patent: 4869780 (1989-09-01), Yang et al.
"Monolithic Integration of InGaAsP/InP Semiconductor Lasers Using the Stop-Cleaving Technique", Arsam Antreasyan et al., 8106 IEEE Journal of Quantum Electronics OE-22 (1986) Jul., No. 7, New York, U.S.A. pp. 1064-1072.
"Surface-Emitting GaInAsP/InP Laser with Low Threshold Current & High Efficiency", by Liau et al., Appl. Phys. Lett. 46(2), Jan. 15, 1985, Am. Institute of Physics, pp. 115-117.
"GaAs/GaAlAs Active-Passive-Interference Laser" by H. K. Choi, Electronics Letters, Apr. 14, 1983, vol. 19, No. 8, pp. 302-303.
"Etched-Groove Coupled-Cavity Vapor-Phase-Transported Window Lasers" at 1.55 um, L. A. Coldren et al., Appl. Phys. lett. 46(1), Jan. 1, 1985, American Institute of Physics, pp. 5-7.
"GaInAsP/InP Stripe Lasers with Etched Mirrors Fabricated by a Wet Chemical Etch", B. I. Miller, Appl. Phys. Lett. 37(4), Aug. 15, 1980, American Institute of Physics, pp. 339-341.
"Large Optical Cavity GaAs-(GaAl) As Injection Laser with low-loss distributed Bragg reflectors" by H. Namizaki, et al., Appl. Phys. Lett., vol. 31, No. 2, Jul. 15, 1977, American Institute of Physics, pp. 122-124.
Kappeler Franz
Wolf Thomas
Epps Georgia
Siemens Aktiengesellschaft
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