Bookham Technology Limited

Oclaro Technology Limited

Achim Thies

Berthold Schmidt

Christoph S Harder

Susanne Pawlik

Boris Sverdlov

Silke Traut

Semiconductor laser diodes, particularly high power ridge waveguide laser diodes, are often used in opto-electronics as so-called pump laser diodes for fiber amplifiers in optical communication lines. To provide the desired high power output and stability of such a laser diode and avoid degradation during use, the present invention concerns an improved design of such a device, the improvement concerns a method of suppressing the undesired first and higher order modes of the laser which consume energy and do not contribute to the optical output of the laser, thus reducing it's efficiency. This novel effect is provided by a structure comprising CIG&#x2014;for Complex Index Guiding&#x2014;elements on top of the laser diode, said CIG being established by fabricating CIG elements consisting of one or a plurality of layers and containing at least one layer which provides the optical absorption of undesired modes of the lasing wavelength. This CIG preferably contains an insulating layer as a first contact layer to the semiconductor. The CIG elements are manufactured by a selected sequence of processing steps, in particular several masking steps, and are specifically shaped, both in thickness and coverage of the laser's semiconductor body, to provide desired suppression characteristics. Further, the CIG elements may be combined with the contact layer usually providing the electrical input power to the laser diode.

High power semiconductor laser diode

Semiconductor laser diodes, particularly high power AlGaAs-based ridge-waveguide laser diodes, are often used in opto-electronics as so-called pump laser diodes for fiber amplifiers in optical communication lines. To provide the desired high power output and stability of such a laser diode and avoid degradation during use, the present invention concerns an improved design of such a device, the improvement in particular significantly minimizing or avoiding (front) end section degradation of such a laser diode and significantly increasing long-term stability compared to prior art designs. This is achieved by establishing one or two 'unpumped end sections' of the laser diode. One preferred way of providing such an unpumped end section at one of the laser facets () is to insert an isolation layer () of predetermined position, size, and shape between the laser diode's semiconductor material and the usually existing metallization (). A further embodiment shows separate, further isolation layers () extending along the laser diode, potentially abutting the ridge waveguide of the laser.

Semiconductor laser diodes, particularly high power ridge waveguide laser diodes, are often used in opto-electronics as so-called pump laser diodes for fiber amplifiers in optical communication lines. To provide the desired high power output and stability of such a laser diode and avoid degradation during use, the present invention concerns an improved design of such a device, the improvement in particular consisting in a way of suppressing the undesired first and higher order modes of the laser which consume energy and do not contribute to the optical output of the laser, thus reducing it's efficiency. Essentially, the novel effect is provided by a structure comprising CIG&#x2014;for Complex Index Guiding&#x2014;elements on top of the laser diode. These CIG elements consist of one or a plurality of layers and must contain at least one layer which provides the optical absorption of undesired modes of the lasing wavelength and preferably contains an insulating layer as a first contact layer to the semiconductor. The CIG elements may be specifically shaped, both in thickness and coverage of the laser's semiconductor body, to provide desired suppression characteristics. Further, the CIG elements may be combined with the contact layer usually providing the electrical input power to the laser diode.

High power semiconductor laser diode and method for making such a diode

Semiconductor laser diodes, particularly high power AlGaAs-based ridge-waveguide laser diodes, are often used in opto-electronics as so-called pump laser diodes for fiber amplifiers in optical communication lines. To provide the desired high power output and stability of such a laser diode and avoid degradation during use, the present invention concerns an improved design of such a device, the improvement in particular significantly minimizing or avoiding (front) end section degradation of such a laser diode and significantly increasing long-term stability compared to prior art designs. This is achieved by establishing one or two &ldquo;unpumped end sections&rdquo; of the laser diode. One preferred way of providing such an unpumped end section at one of the laser facets ( ) is to insert an isolation layer ( ) of predetermined position, size, and shape between the laser diode's semiconductor material and the usually existing metallization ( ).

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Zurich, Switzerland

Achim Thies