Corning Lasertron, Incorporated

Corning Incorporated

Randal A Salvatore

Richard T Sahara

Hanh Lu

Dale C Flanders

Arvind Baliga

An integrated semiconductor device comprising a wavelength-tunable laser, such as a distributed Bragg reflector (DBR) laser, where the laser has a gain section that includes an active layer, and a grating section that includes an active layer and a current-induced grating. A first electrical contact is provided over the gain section to supply current to the gain section and control the output power of the light, and a second electrical contact is provided over the grating section to supply current to the grating section and control the wavelength of the emitted light. The current-induced grating of the present device causes gain in the active layer of the laser to be modulated spatially in the direction of light propagation, thus resulting in only one of the degenerate Bragg modes to oscillate. As the degeneracy of the Bragg modes is broken by current-injection, and not facet reflection, substantially continuous wavelength tuning is possible without the deleterious phenomenon of &ldquo;mode hopping.&rdquo; The present design does not utilize a phase section, and thus eliminates the complex three-way interaction between the gain section, grating section, and a phase section. Alternative grating designs include gain-coupled gratings, complex-coupled gratings, and fractional wave shifted gratings, with relatively strong coupling products (&kgr;L>1.5), which do not rely on facet reflections to break the degeneracy of the Bragg modes.

Tunable laser device for avoiding optical mode hops

A semiconductor pump laser comprises a ridge waveguide electro-optical structure, which converts a ridge injection current into light and an integrated wavelength selective facet reflector. This reflector controls the longitudinal modal operation of the pump laser. Specifically, the reflector comprises a first reflective structure for reflecting light to return through the ridge waveguide electro-optical structure. A second reflective structure provides wavelength-selective reflectivity when operating in combination with the first reflective structure. In other words, the phase of light reflected from the first and second reflective structures is such that the net reflectivity of the facet is wavelength selective, or favors certain wavelengths over other wavelengths.

Mode-selective facet layer for pump laser

An integrated electroabsorption modulated laser (EML) device includes a distributed feedback (DFB) laser and modulator. The DFB laser includes an active layer and a complex index grating. The modulator includes an active layer. The EML device includes a first electrical contact over the DFB laser and a second electrical contact over the modulator. The EML device includes a stop etch layer above the active layer of both the DFB laser and the modulator. An electroabsorption modulated partial grating laser (EMPGL) device includes a distributed feedback (DFB) laser, an amplifier and a modulator. An ion implantation region in the EML/EMPGL devices provides electrical isolation between the DFB laser/amplifier and the modulator.

Electroabsorption modulated laser

A semiconductor electro-optical device such as a laser or modulator comprises a ridge of active and wave-guiding semiconductor layers extending between two facets. In the preferred embodiment, cavity length is relatively long, i.e., the facets are separated by greater than a millimeter. This lowers the current densities in the ridge for the same output beam power. Further, an oxygen-free passivation layer is continuously formed over at least one of the facets to prevent surface corrosion and avoid electrical surface traps. However, a standing-wave-shifted coating is further used on the facet with the passivation layer to reduce the electric field magnitude in the passivation layer.

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Watertown, MA, United States of America

Randal A Salvatore