Broad-area MOPA device with leaky waveguide beam expander

A coherent light source comprising

• at least one laser oscillator,
• at least one leaky waveguide beam expander having an elongated antiguide core of at least a first effective refractive index which is opticallly coupled to said laser oscillator to receive lightwaves therefrom, said beam expander also having at least one radiated-wave receiving region of at least a second effective refractive index that is greater than said first refractive index, said radiated-wave receiving region laterally disposed on at least one side of said antiguide core to receive lightwaves radiated laterally out of said antiguide core, and
• at least one broad area optical power amplifier region optically coupled to said at least one beam expander to receive said laterally radiated lightwaves from said beam expander, said amplifier region having excitation means associated therewith for amplifying said lightwaves, wherein said elongated antiguide core is tapered with a core width that decreases along the length of the antiguide core, said broad area optical power amplifier receiving diverging lightwaves from said beam expander.

A coherent light source comprising

• at least one laser oscillator,
• at least one leaky waveguide beam expander having an elongated antiguide core of at least a first effective refractive index which is optically coupled to said laser oscillator to receive lightwaves therefrom, said beam expander also having at least one radiated-wave receiving region of at least a second effective refractive index that is greater than said first refractive index, said radiated-wave receiving region laterally disposed on at least one side of said antiguide core to receive lightwaves radiated laterally out of said antiguide core, and
• at least one single spatial mode preamplifier section disposed between each said laser oscillator and said at least one beam expander, said preamplifier section having conductive contact means for amplifying lightwaves received from said laser oscillator.

A coherent light source comprising at least one laser oscillator,

• a leaky waveguide beam expander having only one elongated antiguide core of a first effective refractive index which is optically coupled to said laser oscillator to receive lightwaves therefrom, said beam expander also having at least one radiated-wave receiving region of at least a second effective refractive index that is greater than said first refractive index, said radiated-wave receiving region laterally disposed on at least one side of said antiguide core to receive lightwaves radiated laterally out of a length of said antiguide core, said laterally radiated lightwaves forming a wide light beam propagating laterally in said receiving region from said antiguide core to an output end of said receiving region, the opposite side of said antiguide core from said radiated-wave receiving region having a cladding region with a third refractive index that is less than said first refractive index of said antiguide core.

A coherent light source comprising

• at least one laser oscillator, and
• at least one leaky waveguide beam expander having an elongated antiguide core of at least a first effective refractive index which is optically coupled to said laser oscillator to receive lightwaves therefrom, said beam expander also having at least one radiated-wave receiving region of at least a second effective refractive index that is greater than said first refractive index, said radiated-wave receiving region laterally disposed on at least one side of said antiguide core to receive lightwaves radiated laterally out of said antiguide core, wherein the opposite side of said antiguide core from said radiated-wave receiving region has a plurality of antiresonant regions of alternating first and second refractive indices and half wavelength widths so as to reflect lightwaves radiated into said antiresonant regions back towards said radiated-wave receiving region.

A coherent light source comprising

• at least one laser oscillator, and
• at least one leaky waveguide beam expander having an elongated antiguide core of at least a first effective refractive index which is optically coupled to said laser oscillator to receive lightwaves therefrom, said beam expander also having at least one radiated-wave receiving region of at least a second effective refractive index that is greater than said first refractive index, said radiated-wave receiving region laterally disposed on at least one side of said antiguide core to receive lightwaves radiated laterally out of said antiguide core, wherein said radiated-wave receiving region has an index loading layer formed in a transverse cladding layer proximate to an active region, said index loading layer having a refractive index that is higher than that of said cladding layer.

A broad area coherent light source comprising

• a semiconductor chip with an active gain region, a single elongated antiguide core associated with said gain region for guiding lightwaves generated in said gain region, and a radiated-wave receiving region disposed on a side of said antiguide core with a higher effective refractive index than an effective refractive index of said antiguide core to receive lightwaves laterally radiated from a length of said antiguide core, said laterally radiated lightwaves forming a wide light beam propagating laterally in said receiving region from said antiguide core to an output end of said receiving region,
• feedback means for defining a resonant optical cavity, said antiguide core and said radiated-wave receiving region at least partially located within said cavity, and
• excitation means for pumping said active gain region.

A broad area MOPA device comprising

• a semiconductor chip with an active gain region, an elongated antiguide core associated with said gain region for guiding lightwaves generated in said gain region, and a radiated-wave receiving region disposed on a side of said antiguide core with a higher effective refractive index than an effective refractive index of said antiguide core to receive lightwaves laterally radiated from said antiguide core,
• excitation means for pumping said active gain region, and
• feedback means for defining a resonant optical cavity, wherein said antiguide core and said radiated-wave receiving region are partially within and partially outside of said resonant optical cavity, with one reflector of said feedback means positioned along said antiguide core and another reflector of said feedback means positioned at an end of said antiguide core.

A semiconductor broad area light amplifying device comprising

• a single elongated antiguide core of a first effective refractive index adapted to receive a narrow light beam from a light source,
• a radiated-wave receiving region disposed along at least one side of said antiguide core with a second effective refractive index larger than said first refractive index to receive light laterally radiated from a length of said antiguide core, said laterally radiated light forming a wide light beam propagating laterally in said receiving region from said antiguide core to an output end of said receiving regions, and
• a broad area optical power amplifier laterally disposed at said output end of said radiated-wave receiving region to receive said wide light beam therefrom and amplify said beam as it continues to propagate laterally in said amplifier.

A monolithic, broad area, master oscillator power amplifier (MOPA) device comprising

• a single spatial mode laser oscillator,
• a broad area optical power amplifier, and
• a transverse leaky waveguide coherent beam expander coupled between said laser oscillator and said optical power amplifier, said beam expander having an elongated antiguide core of a first refractive index disposed to receive and guide lightwaves from said single spatial mode laser oscillator, said beam expander also having a radiated-wave receiving region laterally disposed along at least one side of said antiguide core and having a second refractive index greater than said first refractive index of said antiguide core to receive lightwaves laterally radiated from said antiguide core as a wide coherent beam, said broad area optical power amplifier disposed at an output of said beam expander to receive and amplify said wide coherent beam from said radiated-wave receiving region.