Mehrdad Te Mohebi

US Patent:

6859335, Feb 22, 2005

Filed:

Nov 13, 2003

Appl. No.:

10/714274

Inventors:

Ming Lai - Pleasanton CA, US
Zhimin Qu - Pleasanton CA, US
Mehrdad Mohebi - Pleasanton CA, US

International Classification:

G02B027/02
G01B009/00
G01B011/02

US Classification:

359800, 359798, 356515, 356124

Abstract:

The present invention contemplates a programmed displacement to prolong the usage life of UV crystal for deep UV generation by displacing step by step the crystal with interval between steps much shorter than the degradation time of the crystal. Meanwhile, the present invention contemplates the programmed displacement to obtain stable UV generation by avoiding defect locations of the crystal. Further, the present invention contemplates the programmed displacement to achieve optimal stability in UV power for each layer of UV ablation in photo-refractive surgery.

US Patent:

7003005, Feb 21, 2006

Filed:

Apr 3, 2003

Appl. No.:

10/406946

Inventors:

Ming Lai - Pleasanton CA, US
Zhimin Qu - Pleasanton CA, US
Mehrdad Mohebi - Dublin CA, US

International Classification:

H01S 3/13
H01S 3/08
H01S 3/082

US Classification:

372 30, 372 92, 372 97

Abstract:

The present invention contemplates a simplified laser oscillator-amplifier system for deep UV generation. The simplified system employs same type of gain media in both the oscillator and the amplifier and utilizes a single pump pulse split to pump both the oscillator and the amplifier. A short cavity oscillator is operated near lasing threshold to produce a seed pulse with a narrow spectral bandwidth and long pulse duration. A short cavity amplifier is Q-switched to amplify the seed pulse to produce a single short pulse with good energy extraction efficiency. The amplifier is simply a short cavity, Q-switched laser. Short pulse is obtained with short cavity length and high gain of the amplifier. Consequently, the simplified laser oscillator-amplifier system can accommodate a long pump pulse to produce a nanosecond pulse suitable for deep UV laser generation.

US Patent:

6792027, Sep 14, 2004

Filed:

Mar 10, 2003

Appl. No.:

10/385961

Inventors:

Ming Lai - Plesanton CA 94588
Mehrdad Mohebi - Pleasanton CA 94588
Zhimin Qu - Pleasanton CA 94588

International Classification:

H01S 310

US Classification:

372 97, 372 25, 372 30, 372 72, 372 92, 372 99

Abstract:

The present invention contemplates an integrated oscillator-amplifier system for deep UV generation. The system employs a long cavity oscillator to lengthen the pulse build-up time and to control the pulse spectral bandwidth. Meanwhile the system employs a short cavity amplifier to shorten the energy extraction time to produce a single short pulse with good energy extraction efficiency. The system further integrates the oscillator and the amplifier by inserting the amplifier cavity inside the oscillator cavity via a mirror of low reflectivity. As a result, the integrated system has a long build-up time to generate a seed pulse in the long cavity oscillator and has a short energy extraction time to generate a short amplified single pulse in the short cavity. Consequently, the integrated system can accommodate a relatively long pump pulse to produce a single short amplified pulse suitable for deep UV laser generation.