Wavelength selector for tunable laser

A wavelength selector comprising:

• a diffraction grating disposed at a grazing angle to an incident beam of light;
• and
• first reflecting means disposed so as to receive a diffracted beam of light from said grating and to reflect it back to said grating, thereby to provide a second diffraction of said incident beam,
• said first reflecting means comprising a cylindrical mirror.

Laser apparatus including a wavelength selector comprising:

• a diffraction grating disposed at a grazing angle to an incident beam of light;
• first reflecting means comprising a cylindrical mirror and disposed so as to receive a diffracted beam of light from said grating and to reflect it back to said grating, thereby to provide a second diffraction of said incident beam;
• and
• second reflecting means associated with said first reflecting means so as to define a laser cavity between said first and second reflecting means.

A wavelength selector comprising:

• a diffraction grating disposed at a grazing angle to an incident beam of light;
• first reflecting means disposed so as to receive a diffracted beam of light from said grating and to reflect it back to said grating, thereby to provide a second diffraction of said incident beam,
• said first reflecting means being rotatably mounted for providing selectable wavelength tuning, and
• mounting means fixed with respect to said first reflecting means for rotation together therewith and an etalon disposed intermediate said diffraction grating and said first reflecting means and rotatably mounted onto said mounting means.

Laser apparatus including a wavelength selector comprising:

• a diffraction grating disposed at a grazing angle to an incident beam of light;
• first reflecting means disposed so as to receive a diffracted beam of light from said grating and to reflect it back to said grating, thereby to provide a second diffraction of said incident beam, said first reflecting means being rotatably mounted for providing selectable wavelength tuning;
• mounting means fixed with respect to said first reflecting means for rotation together therewith and an etalon disposed intermediate said diffraction grating and said first reflecting means and rotatably mounted onto said mounting means;
• and
• second reflecting means associated with said first reflecting means so as to define a laser cavity between said first and second reflecting means.