Diamond laser crystal and method manufacturing the same

A method for manufacturing a diamond laser crystal comprising the steps of doping with one of boron and nickel a synthetic type Ib diamond having a (111) plane growth sector taking up at least 60% of the diamond's volume;

• irradiating said synthetic diamond with an electron or neutron beam;
• thermally treating said synthetic diamond under a pressure within the range of 3 to 7 GPa at a temperature within the range of 1500.degree. to 2500.degree. C. for at least five hours after said step of irradiating said synthetic diamond with said electron or neutron beam;
• again irradiating said synthetic diamond with an electron or neutron beam after said thermal treating step;
• and holding said synthetic diamond under a vacuum atmosphere at a temperature within the range of 1300.degree. to 1600.degree. C. for at least five hours.

A method for manufacturing a diamond laser crystal comprising the following steps:

• preparing a synthetic type Ib diamond having a (111) plane growth sector taking up at least 60% of the diamond's volume;
• thermally treating said synthetic diamond under high temperature and high pressure sufficient for converting type Ib nitrogen contained in said synthetic diamond to type IaA nitrogen;
• irradiating said synthetic diamond with an electron or neutron beam thereby to generate vacancies in said synthetic diamond;
• first annealing said synthetic diamond under a pressure of not more than 10.sup.-1 Torr at a temperature within the range of 600.degree. to 1200.degree. C. for at least five hours, and further annealing said synthetic diamond under said pressure of not more than 10.sup.-1 Torr at an increased temperature within the range of 1300.degree. to 1600.degree. C. for at least five hours after said first annealing step.