Laser-diode pumped solid-state laser apparatus, optical scanning apparatus, image forming apparatus and display apparatus

An optical scanning apparatus scanning a surface by an optical beam, said optical scanning apparatus comprising at least one laser-diode pumped solid-state laser apparatus each comprising:

• at least one laser diode producing a pumping laser light;
• at least one laser light generator comprising a monocrystalline substance doped with a dopant element and pumped with said pumping laser light from said at least one laser diode,
• said monocrystalline substance containing said dopant element with a concentration profile such that said dopant element increases a concentration thereof in a direction perpendicular to a laser oscillation direction gently in the form of a slope from a near zero concentration, wherein said monocrystalline substance is a plate-like crystal having a thickness direction in a laser oscillation direction, the crystal having two surfaces with widths greater than the thickness of the crystal, and wherein one surface is reflective and the other surface is transmissive;
• at least one mirror provided next to the transmissive surface of the crystal forming a cavity between the mirror and the reflective surface of the crystal;
• and
• at least one optical system comprising a plurality of lenses to inject said pumping laser light into the monocrystalline substance.

An image forming apparatus forming an image on an object by a laser light, said image forming apparatus comprising at least one laser-diode pumped solid-state laser apparatus each comprising:

• at least one laser diode producing a pumping laser light;
• at least one laser light generator comprising a monocrystalline substance doped with a dopant element and pumped with said pumping laser light from said at least one laser diode,
• said monocrystalline substance containing said dopant element with a concentration profile such that said dopant element increases a concentration thereof in a direction perpendicular to a laser oscillation direction gently in the form of a slope from a near zero concentration, wherein said monocrystalline substance is a plate-like crystal having a thickness direction in a laser oscillation direction, the crystal having two surfaces with widths greater than the thickness of the crystal, and wherein one surface is reflective and the other surface is transmissive;
• at least one mirror provided next to the transmissive surface of the crystal forming a cavity between the mirror and the reflective surface of the crystal;
• and
• at least one optical system comprising a plurality of lenses to inject said pumping laser light into the monocrystalline substance.

A display apparatus displaying information by a laser light, said image forming apparatus comprising at least one laser-diode pumped solid-state laser apparatus each comprising:

• at least one laser diode producing a pumping laser light;
• at least one laser light generator comprising a monocrystalline substance doped with a dopant element and pumped with said pumping laser light from said at least one laser diode,
• said monocrystalline substance containing said dopant element with a concentration profile such that said dopant element increases a concentration thereof in a direction perpendicular to a laser oscillation direction gently in the form of a slope from a near zero concentration, wherein said monocrystalline substance is a plate-like crystal having a thickness direction in a laser oscillation direction, the crystal having two surfaces with widths greater than the thickness of the crystal, and wherein one surface is reflective and the other surface is transmissive;
• at least one mirror provided next to the transmissive surface of the crystal forming a cavity between the mirror and the reflective surface of the crystal;
• and
• at least one optical system comprising a plurality of lenses to inject said pumping laser light into the monocrystalline substance.