CN1314176C

CN1314176C - Single-mode micro-cavity semiconductor laser

Info

Publication number: CN1314176C
Application number: CNB031068294A
Authority: CN
Inventors: 国伟华; 黄永箴
Original assignee: Institute of Semiconductors of CAS
Current assignee: Institute of Semiconductors of CAS
Priority date: 2003-03-03
Filing date: 2003-03-03
Publication date: 2007-05-02
Anticipated expiration: 2023-03-03
Also published as: CN1527449A

Abstract

The present invention relates to a triangular resonator semiconductor laser. The present invention comprises a flat plate waveguide of a common edge transmitting laser. The flat plate waveguide is composed of a lower limiting layer, an active region and an upper limiting layer. The outer region of an equilateral triangle is corroded to the lower limiting layer or a substrate. The region of the equilateral triangle, which is not corroded, is used as a resonator. A triangular edge is used as a reflector surface. The present invention is characterized in that a hole is arranged at the center point of the equilateral triangle to control different degenerate states.

Description

The single mode microcavity semiconductor laser

Technical field

The present invention relates to semiconductor laser and fiber waveguide device (or semiconductor device), more specifically, the present invention relates to a kind of single mode microcavity semiconductor laser that can control the equilateral-triangle resonance cavity of degenerate mode.

Background technology

Resonant cavity plays the effect of feedback light and the relevant enhancement effect of realization light in semiconductor laser, for realizing that this function can have the resonant cavity of multiple structure, as Fabry one Perot cavity that constitutes by parallel cleavage surface, cause the distribution bragg reaction cavity of light feedback by periodic refractive index or change in gain, little dish structure with total reflection Whispering-gallery-mode, and adopt resonant cavity of equilateral triangle or the like.In equilateral-triangle resonance cavity, fundamental transverse mode has the quality factor more much higher than high-order transverse mode, therefore is easy to realize fundamental transverse mode work.The selection of different longitudinal modes then depends on pattern wavelength interval bigger between them.But there are two degenerate states to have same transverse mode and longitudinal mode number, therefore how realize that the control to degenerate state is the key that obtains the single mode semiconductor laser device with equilateral-triangle resonance cavity.According to the symmetry of equilateral triangle, we can further classify the pattern in the equilateral-triangle resonance cavity.We find for the longitudinal mode number is two degenerate states of the pattern of 6 integral multiple, and one of them attitude aligns the characteristics that leg-of-mutton all minute surfaces operations have symmetry, is called A ₁Attitude, another attitude then have antisymmetric characteristics to all minute surface operations, are called A ₂Attitude.The longitudinal mode number is not that the degenerate state of the pattern of 6 integral multiple does not then have so tangible symmetry, and we are called the E attitude this attitude.Importantly for the TM mould, leg-of-mutton central point is A ₁The maximum of attitude electric field, A ₂At the zero point of attitude electric field, the E attitude then falls between.Like this when we when the central point of equilateral-triangle resonance cavity etches an aperture, see Fig. 1, A ₁Attitude will be experienced maximum scattering loss, A ₂The scattering loss minimum of attitude, and the scattering loss of E attitude is between A ₁Attitude and A ₂Between the attitude.Adopt the simulation of Finite Difference-Time Domain fractional value, we find that when triangle center point was introduced aperture, the quality factor of homomorphism variation difference very greatly: A in refractive index is 3.2 two-dimentional equilateral-triangle resonance cavity ₁Attitude and the quality factor with E attitude of mirror symmetry sharply reduce; A ₂The aperture that the quality factor of attitude is just thought aperture just a bit descends during greater than 0.3～0.4 micron, sees (0, the 24) attitude of Fig. 2 and (0,36) attitude of Fig. 3; And the quality factor with E attitude of minute surface skew-symmetry compares A ₁Attitude and the quality factor with E attitude of mirror symmetry descend slowly, but have also reduced by one more than the magnitude when small aperture is 0.3～0.4 micron, see (0, the 26) attitude of Fig. 2 and (0,38) attitude of Fig. 3.Therefore introducing the aperture at the central point of equilateral-triangle resonance cavity is 0.3～0.4 micron duck eye, can select the A of the TM mould with high-quality-factor ₂Attitude, and A ₁Attitude and E attitude suppress down, thereby realize single module lasing of no degenerate mode.And A ₂The pattern wavelength interval of attitude is three times of longitudinal mode wavelength interval of equilateral-triangle resonance cavity, more helps realizing single mode operation.For the TE mould, introducing the aperture duck eye at the central point of equilateral-triangle resonance cavity, can select the A of TE mould equally with high-quality-factor ₂Attitude, just the aperture is better at 0.2～0.3 micron.

Summary of the invention

The objective of the invention is in equilateral-triangle resonance cavity to realize control, thereby obtain the single mode microcavity semiconductor laser degenerate mode.To control different degenerate states

Core concept of the present invention is to introduce the aperture of small-bore at the central point of triangle resonant cavity, and using planar technology realizes the microcavity semiconductor laser of single module lasing.In the triangle resonant cavity, the A of TM mould ₂Attitude is zero in the electric field strength of the central point of triangle resonant cavity, and the influence of its acceptor center point aperture is minimum, when the aperture of aperture is 0.3 micron, and A ₂The frequency of attitude and quality factor almost do not change, and the quality factor of other attitude will reduce by one more than the magnitude, therefore can realize the single mode microcavity semiconductor laser.The quality factor of TE mould also has same character with the variation of small aperture.

The objective of the invention is to realize by following scheme:

A kind of simple vacuum molding production, structure comprises the planar waveguide that is made of lower limit layer, active area and upper limiting layer, the equilateral triangle perimeter erodes to lower limit layer or substrate, and uncorroded equilateral triangle zone is as resonant cavity, triangle edges is characterized in that as mirror surface: the central point of equilateral triangle have an aperture at 0.1～0.5 micron aperture to control different degenerate states.

Description of drawings

For further specifying technology contents of the present invention, after being described in more detail in below in conjunction with embodiment and accompanying drawing, wherein:

Fig. 1 is the structure chart that the present invention has the semiconductor laser device with equilateral-triangle resonance cavity of the etched hole of controlling degenerate state.

Fig. 2 is the TM mould A of (0,24) for the pattern count that adopts the simulation of Finite Difference-Time Domain fractional value to draw ₂Attitude and pattern count are the variation with the etching aperture of the mode frequency of minute surface antisymmetry TM mould E attitude of (0,26) and quality factor.The equilateral triangle zone length of side is 3 microns, refractive index 3.2.

Fig. 3 is the TM mould A of (0,36) for the pattern count that adopts the simulation of Finite Difference-Time Domain fractional value to draw ₂Attitude and pattern count are the variation with the etching aperture of the mode frequency of minute surface antisymmetry TM mould E attitude of (0,38) and quality factor.The equilateral triangle zone length of side is 5 microns, refractive index 3.2.

Fig. 4 makes the step schematic diagram of single mode semiconductor laser device with equilateral-triangle resonance cavity for the present invention.

Wherein: Fig. 4 a is the end view of step 1.

Fig. 4 b is the top view of step 2.

Fig. 4 c is the top view of step 3.

Embodiment

At first see also shown in Figure 1ly, have the schematic diagram of the equilateral-triangle resonance cavity 40 of etched hole 100.A kind of simple vacuum molding production of the present invention, structure comprises that common edge-emitting laser is by lower limit layer, the planar waveguide that active area and upper limiting layer constitute, the equilateral triangle perimeter erodes to lower limit layer or substrate, and uncorroded equilateral triangle zone is as resonant cavity, triangle edges is as mirror surface, at the central point of equilateral triangle 40 hole 100 arranged, to control different degenerate states.The aperture in wherein said hole 100 is at 0.1～0.5 micron.

The outside of equilateral-triangle resonance cavity etches into substrate layer 520, all is limited in the etching end face with Assured Mode light field cross direction profiles.

Fig. 2 has that pattern count is the A of (0,24) in the equilateral-triangle resonance cavity of 3 microns of the length of sides of etched hole ₂Attitude and pattern count are the variation with the etching aperture of the mode frequency of minute surface antisymmetry E attitude of (0,26) and quality factor.Pattern count (m, l) representing the transverse mode number is m and the longitudinal mode number is l, (0,24) is that the longitudinal mode number is 24 fundamental transverse mode.When the etching aperture when zero is increased to 0.4 micron, pattern count is the A of (0,24) ₂The quality factor of attitude does not reduce, and pattern count to be the quality factor of the minute surface antisymmetry E attitude of (0,26) reduced a magnitude when the etching aperture is 0.3 micron.A ₁The quality factor of attitude and minute surface symmetry E attitude descends sooner, does not provide among the figure.

Fig. 3 has that pattern count is the A of (0,36) in the equilateral-triangle resonance cavity of 5 microns of the length of sides of etched hole ₂Attitude and pattern count are the variation with the etching aperture of the mode frequency of minute surface antisymmetry E attitude of (0,38) and quality factor.When the etching aperture when zero is increased to 0.3 micron, pattern count is (0,36) A ₂The quality factor of attitude changes very little, and pattern count to be the quality factor of (0,38) minute surface antisymmetry E attitude reduced a magnitude.A ₁The quality factor of attitude and minute surface symmetry E attitude descends sooner, does not provide among the figure.

Fig. 4 is for making the step of simple vacuum molding production shown in Figure 1: Fig. 4 a is that step 1 (end view) promptly adopts methods such as molecular beam epitaxy or metallo-organic compound vapour phase epitaxy to grow on substrate 520 to comprise lower limit layer 18, active layer 16, the common edge-emitting laser slice, thin piece of upper limiting layer and ohmic contact layer 14; Fig. 4 b is step 2 (top view), adopts stripping technology at electrode 12 and the etching barrier layer 15 produced on the epitaxial loayer on the equilateral-triangle resonance cavity 40, and at this moment the outer etched hole place that reaches, equilateral-triangle resonance cavity 40 zones does not have electrode and etching barrier layer; Fig. 4 c etches into substrate 520 for adopting lithographic methods such as reactive ion beam, and remove etching barrier layer 14, and at this moment schematic top view triangle resonant cavity 40 is an electrode layer 12, other zones are substrate layer 520, and place, etching hole is substrate layer 520, perhaps because etching speed is other epitaxial loayer more slowly.

Claims

1, a kind of simple vacuum molding production, structure comprises the planar waveguide that is made of lower limit layer, active area and upper limiting layer, the equilateral triangle perimeter erodes to lower limit layer or substrate, and uncorroded equilateral triangle zone is as resonant cavity, triangle edges is as mirror surface, it is characterized in that: the central point at equilateral triangle has a hole, and to control different degenerate states, described aperture is at 0.1～0.5 micron.