Angled distributed reflector optical device with enhanced light confinement

An optical medium comprising:

• a first region containing a periodic reflector;
• a second region containing no periodic reflector;
• said first and second regions forming an interface therebetween;
• an optical beam propagating within said first and second regions at an angle relative to said periodic reflector but not at normal incidence of said periodic reflector;
• said interface having a normal incidence that is at an angle lying between said periodic reflector normal incidence and a direction of propagation of said beam in said second region.

A optical device comprising:

• a beam of coherent radiation propagating sequentially through a first waveguide region and a second waveguide region, said regions having an interface therebetween;
• said second waveguide region comprising a grating having grooves disposed at a first angle with respect to said propagating beam, said grating being absent from said first waveguide region;
• the interface between said first and second regions disposed at a second angle with respect to a propagating direction of said propagating beam;
• said second angle being greater than said first angle and equal to or less than 90.degree..

A coherent radiation source comprising:

• at least one beam of light propagating along a given path relative to the source;
• a Bragg grating comprising a plurality of periodic reflective means that interact with and deflect said beam of light within the source;
• said reflective means disposed at a first angle .theta..sub.1 to said given path;
• a boundary of said grating lying in said given path, at least a portion of said boundary disposed at a second angle .theta..sub.2 to said given path such that 90.degree.>.theta..sub.2 >.theta..sub.1 >0.degree..

A semiconductor laser device comprising:

• a gain region formed in said device, said gain region having a first light containing region coupled at an interface to a second light containing region;
• a grating structure formed in said device and having an elongated axial direction;
• said first light containing region including at least a portion of said grating structure;
• said second light containing region not containing said grating structure;
• reflective means bordering said second light containing region opposite to said interface, said grating structure axial direction disposed at a first angle (.theta..sub.1) relative to said reflector;
• at least a portion of said interface being disposed along a plane at a second angle (.theta..sub.2) relative to said reflector, said second angle (.theta..sub.2) less than 90.degree..

A semiconductor laser device comprising:

• a light reflector extending along a first plane;
• a grating extending along a second plane at an angle to said first plane which is not of normal incidence with respect to said first plane;
• light propagating along a path that interacts with at least a portion of said grating and being at least partially deflected by said grating;
• a boundary formed along a third plane that intersects said light path, at least a portion of said boundary third plane disposed at an angle to said grating second plane and to said reflector first plane that is within a range of angles between said reflector first plane and said grating second plane.

A coherent radiation source comprising:

• a substantially collimated beam of light propagating along a given path relative to the source;
• a Bragg grating comprising a plurality of substantially parallel grooves formed in said source having deflecting surfaces that interact with and deflect said beam of light within the source;
• said grating grooves disposed at a first angle (.theta..sub.1) to a plane normal to said given path;
• a boundary of said grating lying in said given path, at least a portion of said boundary disposed at a second angle (.theta..sub.2) to said plane such that .theta..sub.1 >.theta..sub.2 >0.

A coherent radiation source comprising:

• at least one active region for generating radiation;
• first and second reflective means defining a resonant cavity therebetween, generated radiation propagating along a path between said reflective means;
• said resonant cavity having at least two parts comprising a first part including distributive reflective means disposed at angle to said first and second reflective means within at least a portion of said first part for interacting and laterally deflecting portions of the propagating radiation along said path and a second part formed between one of said reflective means and a boundary formed between said first and second parts, said second part not containing said distributive reflective means;
• said boundary disposed at an angle relative to said one reflective means such that laterally deflected propagating light in said first part when crossing said boundary toward said one reflective means is oriented at said boundary to be substantially perpendicular to a plane of said one reflective means.

A coherent radiation source comprising:

• at least one beam of light propagating in a cavity along a given path within the source between end faces of the cavity;
• at least a first portion of the propagating path including a Bragg grating, said grating formed at a first angle relative to said cavity end faces;
• at least a second portion of the propagating path formed between one of said end faces and said grating portion;
• and
• an angular interface formed between said first and second portions, at a second angle relative to said cavity end faces, said second smaller than said first angle.

A laser source system comprising:

• an angled grating laser source having an optical cavity with an angled Bragg grating in a first portion of said cavity for selecting, in combination, a single spatial mode and a single lasing frequency light as an output from said source, said light propagating in said first portion as first and second wave components;
• at least one preferential coupling region in a second portion of said optical cavity of said source between said first portion and said output, said coupling region absent of said angled Bragg grating and for coupling light propagating in said first portion into one of said propagating wave components;
• a nonlinear frequency conversion device having a characteristic wavelength in optical communication with the laser source;
• said output from said laser optically coupled to said nonlinear frequency conversion device wherein said single lasing frequency is selected by said angled Bragg grating to at least approximately match the characteristic wavelength of said nonlinear frequency conversion device.

A semiconductor laser comprising:

• an active region for light generation when electrically excited and propagating in an optical cavity;
• reflective means for providing feedback in said optical cavity;
• an optical grating in at least a portion of said optical cavity wherein light propagating in said optical cavity propagates at a non-normal incidence to said optical grating into two different wave components;
• and
• at least one other portion of said optical cavity optically coupled to said grating portion of said optical cavity for receiving light propagating in said grating portion for permitting the coupling of one of said two wave components into the other of said wave components.

A method of coupling light propagating in an optical device in at least two different waves, respectively propagating in first and second directions in a direction of a mean optical axis, into a single preferred light propagation direction, comprising the steps of:

• directing the waves through a first optical region having a coupling structure causing either of the waves to interact with the structure and couple mutually one into the other as they propagate in the direction of the mean optical axis;
• providing an interface disposed at an angle transverse to the mean optical axis for intercepting the mutually coupling waves and causing only first of the waves to pass through the interface with a substantial portion of the second wave being coupled into the first wave at or near the interface;
• and
• directing thereafter the first wave through a second optical region absent the coupling structure such that the first wave cannot again couple back into the second wave in the second optical region, the direction of propagation of the first wave in the second region comprising the single preferred light propagation direction.