Ii-vi Delaware, Inc.

Ii-vi Incorporated

Ii-vi Laser Enterprise Gmbh

Other

Oclaro Technology Limited

Norbert Lichtenstein

Lukas Mutter

Giovanni Barbarossa

Julien Boucart

Giuseppe Tandoi

Stefan Weiss

Martin Krejci

René Todt

Andre Bisig

Wen-Qing Xu

Andrew Cannon Carter

Elgin E Eissler

Thomas E Anderson

Chao Liu

Abram Jakubowicz

Boris Sverdlov

Charles J Kraisinger

Michael Schwarz

Jürgen Müller

Bonifatius Wilhelmus Tilma

Jarkko Telkkälä

Hans-Ulrich Pfeiffer

Jörg Troger

André Bisig

Hans Jörg Troger

Modification of the topology of selected regions of individual VCSEL devices during fabrication is utilized to provide an array output beam with specific characteristics (e.g., 'uniform' output power across the array). These physical features include at least the width of the metal aperture, the width of the oxide aperture, and/or the geometry of the contact ring structure on the top of the VCSEL device. The modifications may also function to adjust the numerical apertures (NAs) of the devices, the beam waist, wallplug efficiency, and the like.

Tailoring of high power VCSEL arrays

Modification of the topology of selected regions of individual VCSEL devices during fabrication is utilized to provide an array output beam with specific characteristics (e.g., 'uniform' output power across the array). These physical features include the width of the metal aperture, the width of the modal filter, and/or the geometry of the contact ring structure on the top of the VCSEL device. The modifications may also function to adjust the numerical apertures (NAs) of the devices, the beam waist, wallplug efficiency, and the like.

An array layout of VCSELs is intentionally mis-aligned with respect to the xy-plane of the device structure as defined by the crystallographic axes of the semiconductor material. The mis-alignment may take the form of skewing the emitter array with respect to the xy-plane, or rotating the emitter array. In either case, the layout pattern retains the desired, row/column structure (necessary for dicing the structure into one-dimensional arrays) while reducing the probability that an extended defect along a crystallographic plane will impact a large number of individual emitters.

VCSEL array layout

A fabrication sequence for an oxide-confined VCSEL includes the deposition of a protective coating over exposed horizontal surfaces to prevent unwanted oxide layers from being formed during the lateral oxidation process used to create the oxide aperture. By preventing the oxidation of these surfaces in the first instance, the opportunity for moisture to gain access to the active region of the VCSEL is eliminated. For example, exposed Al-containing surfaces are covered with a protective coating of dielectric material prior to initiating the conventional lateral oxidation process used to form the oxide aperture of the VCSEL. With the protective coating in place, a conventional fabrication process is resumed, and the protective coating ultimately forms part of the passivation layer used to provide electrical isolation for the final VCSEL device.

Moisture control in oxide-confined vertical cavity surface-emitting lasers

A densely-spaced single-emitter laser diode configuration is created by using a laser bar (or similar array configuration) attached to a submount component of a size sufficient to adequately support the enter laser structure. The surface of the submount component upon which the laser structure is attached is metallized and used to form the individual electrical contacts to the laser diodes within the integrated laser structure. Once attached to each other, the laser structure is singulated by creating vertical separations between adjacent light emission areas. The submount metallization is similarly segmented, creating separate electrodes that are used to individually energize their associated laser diodes.

Densely-spaced laser diode configurations

A composite substrate includes a submount substrate of an alternating pattern of electrically insulative portions, pieces, layers or segments and electrically conductive portions, pieces, layers or segments, and a shaft, back or plate for supporting the alternating pattern of electrically insulative portions and electrically conductive portions. An active device having a P-N junction can be mounted on the submount substrate. The electrically insulative portions, pieces, layers or segments can be formed from diamond while the electrically conductive portions, pieces, layers or segments can be formed from a metal or metal alloy.

Composite substrate with alternating pattern of diamond and metal or metal alloy

A broad area laser diode is configured to include an anti-guiding layer located outside of the active region of the device. The anti-guiding layer is formed of a high refractive index material that serves to de-couple unwanted, higher-order lateral modes (attributed to thermal lensing problems) from the lower-order mode output beam of output signal from the laser diode. The anti-guiding layer is formed using a single epitaxial growth step either prior to or subsequent to the steps used to grow the epitaxial layers forming the laser diode itself, thus creating a structure that provides suppression of unwanted higher-order modes without requiring a modification of specific process steps used to fabricate the laser diode itself.

Broad area laser including anti-guiding regions for higher-order lateral mode suppression

A semiconductor laser diode comprises a semiconductor body having an n-region and a p-region laterally spaced apart within the semiconductor body. The laser diode is provided with an active region between the n-region and the p-region having a front end and a back end section, an n-metallization layer located adjacent the n-region and having a first injector for injecting current into the active region, and a p-metallization layer opposite to the n-metallization layer and adjacent the p-region and having a second injector for injecting current into the active region. The thickness and/or width of at least one metallization layer is chosen so as to control the current injection in a part of the active region near at least one end of the active region compared to the current injection in another part of the active region. The width of the at least one metallization layer is larger than a width of the active region. This arrangement results in substantially uniform current distribution near the front end of the active region. Advantageously, this uniform current density significantly improves the reliability of the laser diode.

Semiconductor laser diodes

A high power laser source comprises a bar of laser diodes having a first coefficient of thermal expansion CTEon a submount having a second coefficient CTEand a cooler having a third coefficient CTE. The submount/cooler assembly shows an effective fourth coefficient CTEdiffering from CTE. This difference leads to a deformation of the crystal lattice of the lasers' active regions by mechanical stress. CTEis selected to be either lower than both CTEand CTEor is selected to be between CTEand CTE. The submount may either comprise layers of materials having different CTEs, e.g., a Cu layer of 10-40 &#x3bc;m thickness and a Mo layer of 100-400 &#x3bc;m thickness, or a single material with a varying CTE. Both result in a CTEvarying across the submount's thickness.

High power semiconductor laser diodes

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Langnau am Albis, Switzerland

Norbert Lichtenstein