Finisar Corporation

Ashish K Verma

Tsurugi Sudo

Sumesh Mani K Thiyagarajan

David Bruce Young

Daniel Francis

Roman Dimitrov

Richard P Ratowsky

Lars Eng

Yuk Lung Ha

Arnold C Chen

Scott Lehmann

Jing Chai

In one example embodiment, a DFB laser includes a substrate; an active region positioned above the substrate; a grating layer positioned above the active region, the grating layer including a portion that serves as a primary etch stop layer; a secondary etch stop layer positioned above the grating layer; and a spacer layer interposed between the grating layer and the secondary etch stop layer.

Distributed feedback laser having enhanced etch stop features

In one example embodiment, a DFB laser includes a substrate, an active region positioned above the substrate, and a grating layer positioned above the active region. The grating layer includes a portion that serves as a primary etch stop layer. The DFB laser also includes a secondary etch stop layer located either above or below the grating layer, and a spacer layer interposed between the grating layer and the active region.

A method for depositing protective coatings on front and rear facets of an optical device, such as a laser die, is disclosed. The protective coatings help prevent laser facet damage common to laser dies manufactured using known processes. In one embodiment, the method for coating the laser die includes placing the laser in an evacuated coating chamber before applying a first coating portion to a first facet of the laser. The first coating portion is applied to the first facet so as to form a protective covering thereon, but is applied at a coating energy that minimizes damage to the as-yet uncoated second facet. The laser is then rotated within the coating chamber, and a full coating is applied to a second facet of the laser. The laser is again rotated, and a full coating is applied atop the first coating portion to the first facet of the laser.

Method for applying protective laser facet coatings

One example disclosed herein relates to a method of at least partially optimizing one or more output performance parameters of a laser die. The method includes an act of identifying one or more output performance parameters to be at least partially optimized, an act of identifying one or more design parameters associated with the one or more output performance parameters, an act of determining a subset of the one or more design parameters that should be varied so as to at least partially effect the one or more output performance parameters, an act of varying the subset of design parameters to produce one or more intermediate results, and an act of using the intermediate results to determine values for the one or more design parameters such that the one or more performance parameters are at least partially optimized.

Optimization of laser parameters to achieve desired performance

Optimizing the regrowth over epitaxial layers during manufacture of a distributed feedback laser. In one example embodiment, a method for depositing an InP regrowth layer on an epitaxial base portion of a distributed feedback laser includes growing a first portion of the regrowth layer at an initial substrate temperature of approximately 580 degrees Celsius to a thickness between approximately 300 Angstroms and approximately 900 Angstroms, increasing the substrate temperature from the initial substrate temperature to an increased substrate temperature of approximately 660 degrees Celsius, growing a second portion of the regrowth layer at the increased substrate temperature, doping a first part of an uppermost layer of the regrowth layer at a concentration of approximately 8.00*10^17/cm3 at the increased substrate temperature, and doping a second part of the uppermost layer of the regrowth layer at a concentration between approximately 1.90*10^18/cm3 and approximately 2.00*10^18/cm3 at the increased substrate temperature.

Epitaxial regrowth in a distributed feedback laser

A method for etching facets of a laser die prior to coating in such a way as to control the formation of oxides and metallic films on the facet is disclosed. In one embodiment, the method includes placing a wafer on which the laser is included in the interior volume of an etching chamber. Nitrogen is introduced into the interior volume to define a nitrogen-rich environment. The laser facet is then etched in the nitrogen-rich environment with argon delivered from an ion gun. In another embodiment, the method includes placing the laser in an ion beam etching chamber, then physically etching the facet of the laser with an ion beam that includes an argon/nitrogen mixture. The laser facet(s) can then be coated as desired. The etching method reduces the incidence of leakage current during operation of the laser die caused by metallic film formation on the facet before coating.

Laser facet pre-coating etch for controlling leakage current

Systems and methods for stripping an optical mode from a semiconductor laser. A waveguide layer with multiple layers is included in the semiconductor laser and is typically arranged beneath the active region. The waveguide layer is configured to match the phase of the second order mode. The waveguide layer does not substantially match the primary optical mode of the laser. By matching the phase of the second order mode, the confinement of the second order mode is reduced and the second order mode strongly couples with the waveguide layer. The optical confinement of the primary mode is not substantially reduced. The side-mode suppression ratio is thereby improved by stripping the second order mode from the active region.

Semiconductor laser with side mode suppression

Systems and methods for stripping an optical mode from a semiconductor laser. A waveguide layer is included in the semiconductor laser and is typically arranged beneath the active region. The waveguide layer is configured to match the phase of the second order mode. The waveguide layer does not substantially match the primary optical mode of the laser. By matching the phase of the second order mode, the confinement of the second order mode is reduced and the second order mode strongly couples with the waveguide layer. The optical confinement of the primary mode is not substantially reduced. The side-mode suppression ratio is thereby improved by stripping the second order mode from the active region.

Embodiments disclosed herein relate to high-speed lasers such as FP and DFB lasers. In one embodiment, the high speed laser comprises a substrate, an active region positioned above the substrate, a mesa positioned above the active region, and one or more layers disposed between the active region and the mesa, wherein the thickness of at least one of the one or more layers is implemented to at least partially minimize the distance between the mesa and active region such that lateral current spreading between the mesa and the active region is at least partially minimized.

Thin INP spacer layer in a high speed laser for reduced lateral current spreading

Semiconductor lasers having a doped active region. In one example embodiment, a laser includes a substrate and a doped active region positioned above the substrate. The doped active region includes a plurality of quantum wells separated by a plurality of barrier layers. The quantum wells and the barrier layers are doped with a doping material with a concentration between about 1*10^16/cm3 to about 1*10^17/cm3.

Semiconductor laser having a doped active layer

A laser diode having a composite passivation layer configured to control parasitic capacitance, especially in high speed laser applications, is disclosed. In one embodiment, a ridge waveguide laser is disclosed and includes: a substrate, an active layer disposed on the substrate, a ridge structure disposed on the active layer, and a contact layer disposed on the ridge structure. A composite passivation layer is disposed substantially laterally to the ridge structure. The composite passivation layer includes a silicon nitride bottom layer, a silicon nitride top layer, and a silicon dioxide middle layer interposed between the bottom and top layers. The passivation layers possess differing stress components that, when combined, cancel out the overall mechanical stress of the passivation layer. This enables relatively thick passivation layers to be employed in high speed laser diodes without increasing the risk of layer stress cracking and laser damage.

Semiconductor laser having low stress passivation layer

Optoelectronic devices, such as optical transmitters and optical amplifiers, are provided. The optoelectronic devices are suitable for use in connection with optical communications systems, and related components and devices, such as may be used in the transmission, reception and processing of data and other information. The optoelectronic devices are implemented as various types of semiconductors. The form, structure, properties and functionality of a particular optoelectronic semiconductor device are determined with reference to the application(s) in connection with which the optoelectronic device is to be employed.

Optoelectronic semiconductor device

Systems and methods for tuning a DBR stack for an optical amplifier. The DBR layers in a mirror of the optical amplifier have a duty cycle that can be altered to tune a location of a channel drop in a gain spectrum. In addition to changing the duty cycle, the DBR stacks can be segmented. The segmented DBR stacks and/or the selected duty cycle tunes a location of a channel drop outside of a range of wavelengths of interest.

Tunable segmented distributed bragg reflector for linear optical amplifier

Systems and methods for extending a linear range of a semiconductor optical amplifier (SOA). A feedback layer is included in an SOA. The optical mode of the SOA is distributed between the feedback layer and the active region. As output optical power increases, the mode confinement of the active region increases and the mode is drawn from the feedback layer into the active region. The increase in the mode confinement offsets a loss of material gain such that the linear range of the SOA is extended. In one embodiment, the modal gain increases an higher output optical powers.

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San Jose, CA, United States of America

Ashish K Verma