Optoelectric Device for High-Speed Data Transfer with Electrooptically Tunable Stopband Edge of a Bragg-Reflector

• US 20090296754A1
• Filed: 07/27/2009
• Published: 12/03/2009
• Est. Priority Date: 06/16/2006
• Status: Active Grant

• Current Assignee: Connector Optics LLC (RTI JSC)
• Original Assignee: VI Systems GmbH
• Inventors: Shchukin, Vitaly, Ledentsov, Nikolai
• Granted Patent: US 8,290,016 B2
• Time in Patent Office: Days
• US Class Current: 372/20
• CPC Class Codes: H01L 27/15 including semiconductor components having potential barriers, specially adapted for light emission
• CPC Class Codes: H01L 33/105 with a resonant cavity structure
• CPC Class Codes: H01S 5/0014 Measuring characteristics or properties thereof measuring techniques per se G01J, G01K, G01N, G01R
• CPC Class Codes: H01S 5/0265 Intensity modulators intra-cavity modulators H01S5/0625
• CPC Class Codes: H01S 5/0601 comprising an absorbing region H01S5/0604, H01S5/0607, H01S5/0615 and H01S5/065 take precedence; bistable laser devices in general G02F3/026
• CPC Class Codes: H01S 5/0607 by varying physical parameters other than the potential of the electrodes, e.g. by an electric or magnetic field, mechanical deformation, pressure, light, temperature
• CPC Class Codes: H01S 5/1221 Detuning between Bragg wavelength and gain maximum
• CPC Class Codes: H01S 5/18302 comprising an integrated optical modulator
• CPC Class Codes: H01S 5/1833 with more than one structure
• CPC Class Codes: H01S 5/2027 Reflecting region or layer, parallel to the active layer, e.g. to modify propagation of the mode in the laser or to influence transverse modes

Abstract

A device contains at least one wavelength-tunable multilayer interference reflector controlled by an applied voltage and at least one cavity. The stopband edge wavelength of the wavelength-tunable multilayer interference reflector is preferably electrooptically tuned using the quantum confined Stark effect in the vicinity of the cavity mode (or a composite cavity mode), resulting in a modulated transmittance of the multilayer interference reflector. A light-emitting medium is preferably introduced in the cavity or in one of the cavities permitting the optoelectronic device to work as an intensity-modulated light-emitting diode or diode laser by applying an injection current. The device preferably contains at least three electric contacts to apply forward or reverse bias and may operate as a vertical cavity surface-emitting light emitter or modulator or as an edge-emitting light emitter or modulator. Using a multilayer interference reflector containing tunable section allows also obtaining a wavelength-tunable laser or a wavelength-tunable resonant cavity photodetector in the case where the optical field profile in the active cavity or cavities is affected by the stopband wavelength shift. Adding additional modulator sections enables applications in semiconductor optical amplifiers, frequency converters or lock-in optical amplifiers.

Claims

1. A semiconductor optoelectronic device comprising:

a) at least one cavity region having at least one resonant wavelength;

b) at least one multilayer interference reflector having an optical power transmittance, a reflectivity stopband, and a reflectivity stopband edge at a wavelength, the multilayer interference reflector having a non-transparent state in which the at least one resonant wavelength of the cavity region is within the reflectivity stopband of the multilayer interference reflector and a transparent state in which the at least one resonant wavelength of the cavity region is out of the reflectivity stopband of the multilayer interference reflector;

c) at least one light generating element comprising a gain region, the light generating element configured to generate light when a forward bias is applied to the gain region; and

d) at least one modulator region configured to modulate an output intensity of the light by electro-optically tuning the wavelength of the reflectivity stopband edge of the multilayer interference reflector such that the multilayer interference reflector is changed between the non-transparent state and the transparent state by the tuning, wherein the tuning varies the optical power transmittance of the multilayer interference reflector at the at least one resonant wavelength of the cavity region;

e) at least three electric contacts configured to apply bias to the modulator region and to the light generating element independently.

2. The semiconductor optoelectronic device of claim 1, wherein the modulator region is configured to tune the wavelength of the reflectivity stopband edge of the multilayer interference reflector with respect to the at least one resonant wavelength of the cavity such that the multilayer interference reflector is tuned between the non-transparent state and the transparent state using a quantum confined Stark effect by applying a reverse bias to tune a component of a refractive index of the modulator region.

3. The semiconductor optoelectronic device of claim 1, wherein the modulator region-is configured to tune the wavelength of the reflectivity stopband edge of the multilayer interference reflector with respect to the at least one resonant wavelength of the cavity such that the multilayer interference reflector is tuned between the non-transparent state and the transparent state using an exciton bleaching effect by injection of non-equilibrium carriers by applying a forward bias.

4. The semiconductor optoelectronic device of claim 1, wherein the modulator region is configured to tune the wavelength of the reflectivity stopband edge of the multilayer interference reflector with respect to the at least one resonant wavelength of the cavity such that the multilayer interference reflector is tuned between the non-transparent state and the transparent state via an injection of electron-hole plasma by applying a forward bias, and wherein the modulator region is undoped.

5. The semiconductor optoelectronic device of claim 1, wherein the modulator region has a refractive index and modulating the refractive index changes the wavelength of the reflectivity stopband edge of the multilayer interference reflector with respect to the at least one resonant wavelength of the cavity such that the multilayer interference reflector is tuned between the non-transparent state and the transparent state and such that an output optical power is modulated.

6. The semiconductor optoelectronic device of claim 1, wherein the gain region is configured to realize a population inversion such that the gain overcomes the overall losses enabling lasing.

7. The semiconductor optoelectronic device of claim 6, wherein the device is selected from the group consisting of:

a) a vertical cavity surface-emitting laser;

b) an edge-emitting laser;

c) a distributed feedback edge-emitting laser;

d) a multi-section edge-emitting laser;

e) a tilted cavity laser; and

f) a light-emitting diode.

8. The semiconductor optoelectronic device of claim 1, wherein the device modulates a transmittance of light through a filter comprising at least one cavity and a multilayer interference reflector by modulating the wavelength of the reflectivity stopband edge of the said reflector.

9. The semiconductor optoelectronic device of claim 1, wherein at least one element of the device is formed of materials selected from the group consisting of:

i) III-V semiconductor materials; and

ii) alloys based on III-V semiconductor materials;

wherein the III-V semiconductor materials are selected from the group of binary compounds of an element A, selected from the group consisting of Al, Ga, and In; and

an element B, selected from the group consisting of N, P, As, and Sb.

12. The semiconductor optoelectronic device of claim 1, wherein the light generated by the light generating element has a wavelength that is not within the reflectivity stopband of the multilayer interference reflector.

14. The semiconductor optoelectronic device of claim 1, wherein the cavity region, the multilayer interference reflector, the light generating element, the modulator region, and the contacts form a monolithic structure.

16. The semiconductor optoelectronic device of claim 12, wherein the resonant cavity, the multilayer interference reflector, the modulator region, the light absorbing element and the contacts form a monolithic structure.

10. A method of controlling an intensity of laser light-emitting from a semiconductor optoelectronic device comprising a resonant cavity having at least one resonant wavelength and a multilayer interference reflector having a reflectivity stopband, a non-transparent state in which the at least one resonant wavelength of the cavity is within the reflectivity stopband of the multilayer interference reflector and a transparent state in which the at least one resonant wavelength of the cavity is out of the reflectivity stopband of the multilayer interference reflector;

at least one modulator region;

at least one light generating element which generates light when a forward bias is applied, and at least three electric contacts,

wherein the multilayer interference reflector is selected such that the wavelength of the reflectivity stopband edge of the multilayer interference reflector is electrooptically tunable by applying a bias, via at least two electric contacts selected from the at least three electric contacts, such that the multilayer interference reflector is changed between the non-transparent state and the transparent state;

the method consisting of the stages of;

a) calibration,

wherein the calibration further comprises the steps of;

i) introducing a microampermeter in the same electrical circuit, where the bias is applied to the modulator region, wherein the microampermeter is capable to measure the photocurrent generated in the modulator upon an applied reverse bias;

ii) applying a bias to the modulator region and to the light generating element independently with the electric contacts;

iii) electrooptically tuning a wavelength of the reflectivity stopband edge of the multilayer interference reflector with respect to a resonant wavelength of the cavity;

iv) varying an optical transmittance of the multilayer interference reflector, such that an output optical power is varied;

v) measuring the photocurrent in the electric circuit of the modulator section under reverse bias, and measuring the output light power of the device;

vi) obtaining the light-photocurrent calibration curves;

and

b) control itself,

wherein this stage further comprises the steps of;

i) applying a bias to the modulator region and to the light generating element independently with the electric contacts;

ii) electrooptically tuning a wavelength of the reflectivity stopband edge of the multilayer interference reflector with respect to a resonant wavelength of the cavity;

iii) varying an optical transmittance of the multilayer interference reflector, such that an output optical power is varied;

iv) measuring the photocurrent in the electric circuit of the modulator section under reverse bias; and

v) adjusting the drive current in the circuit of the active element to keep the requested output power of the device using the calibrated light-photocurrent curves.

13. The method of claim 10, wherein the light generated by the light generating element has a wavelength that is not within the reflectivity stopband of the multilayer interference reflector.

15. The method of claim 10, which further comprises providing the semiconductor optoelectronic device as a monolithic structure.

11. A semiconductor resonant cavity photodetector, comprising:

a) at least one resonant cavity having at least one resonant wavelength;

b) at least one multilayer interference reflector having an optical power transmittance, a reflectivity stopband, and a reflectivity stopband edge at a wavelength, the multilayer interference reflector having a non-transparent state in which the at least one resonant wavelength of the resonant cavity is within the reflectivity stopband of the multilayer interference reflector and a transparent state in which the at least one resonant wavelength of the resonant cavity is out of the reflectivity stopband of the multilayer interference reflector;

c) at least one modulator region configured to modulate the transmittance of the multilayer interference reflector by electro-optically tuning the wavelength of the reflectivity stopband edge of the multilayer interference reflector towards or away from the-at least one resonant wavelength of the resonant cavity such that the multilayer interference reflector is changed between the non-transparent state and the transparent state, wherein the tuning varies the optical transmittance of the multilayer interference reflector at the at least one resonant wavelength of the resonant cavity;

d) at least one light absorbing element which absorbs light and generates a photocurrent when a zero or a negative bias is applied to the light absorbing element; and

e) at least three electric contacts which apply bias to the modulator region and to the light absorbing element independently.