Vertical cavity surface emitting laser with optimized linewidth enhancement factor
AssigneeFinisar Corporation
InventorJames K. Guenter
Life of this patent
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Abstract
A vertical cavity surface emitting laser (VCSEL) optimized for use in self mixing applications. The VCSEL generally includes a bottom distributed Bragg reflector (DBR) mirror formed on a substrate. An active region is formed on the bottom mirror. A top DBR mirror is formed on the active region. A trench is formed in the at least the top mirror. An aperture is oxidized into the VCSEL. At least one of the bottom DBR mirror, the top DBR mirror, the metal contacts, the trench, and/or the aperture is optimized to optimize the linewidth enhancement factor for use in self mixing applications.
Claims15
A method for making an electrical device that includes a vertical cavity surface emitting laser (VCSEL) suitable for self mixing applications, comprising:
- selecting an operating temperature for a VCSEL to be incorporated into the electrical device;
- selecting a laser doppler velocimeter comprising the VCSEL and being configured to measure movement of an object relative to the VCSEL, wherein the VCSEL comprises:
- a bottom DBR mirror formed on a substrate;
- an active region formed on the bottom mirror;
- a top DBR mirror formed on the active region;
- contacts electrically coupled to the active region;
- and
- the VCSEL having a T0 where T0 is defined by the temperature at which a threshold current of the VCSEL is at a minimum and wherein the VCSEL is selected so that the T0 is greater than the selected operating temperature;
- and
- incorporating the laser doppler velocimeter into the electrical device and configuring the electrical device such that the VCSEL operates at the selected operating temperature, thereby making the laser doppler velocimeter sensitive to light reflected back into the VCSEL.
A method for making a sensor, comprising:
- designing a VCSEL comprised of a substrate, a lower DBR mirror, an active region, and an top DBR mirror, the VCSEL having a T0 where T0 is defined by the temperature at which a threshold current of the VCSEL is at a minimum with respect to temperature, the designing of the VCSEL including,
- selecting a design operating temperature for the VCSEL;
- identifying that the VCSEL will be used in a self-mixing application at a the design operating temperature;
- and
- optimizing the VCSEL for the self-mixing application by determining a composition and configuration of the VCSEL that gives the VCSEL a T0 that is higher than the design operating temperature.
Dependencies are inferred from the claim text.