Sacrificial micro-gratings

• US 5,812,319 A
• Filed: 10/31/1995
• Issued: 09/22/1998
• Est. Priority Date: 10/31/1995
• Status: Expired due to Fees

• Current Assignee: United States Of America As Represented By The Secretary Of The Army (Government of the United States of America)
• Original Assignee: The United States Of America As Represented By The Secretary Of The Army
• Inventors: Sonstroem, Jaime
• Primary Examiner(s): Dzerzynski, Paul M.
• Assistant Examiner(s): CHANG, AUDREY Y
• Application Number:
  US08/551,056
• Time in Patent Office: 1,057 Days
• Field of Search: 359/7, 359/15, 359/565, 359/566, 359/568, 359/569, 359/571, 385/36, 385/37, 250/216, 372/20
• US Class Current: 359/569
• CPC Class Codes: G02B 1/12 by surface treatment, e.g. by irradiation
• CPC Class Codes: G02B 5/00 Optical elements other than lenses light guides G02B6/00; optical logic elements G02F3/00
• CPC Class Codes: G02B 5/18 Diffraction gratings holographic optical elements G02B5/32, G03H; integrally combined with optical fibres G02B6/02057; for coupling light guides G02B6/34; integrally combined with optical integrated light guides G02B6/12; grating systems G02B27/44

Abstract

An arrangement and technique for reduced laser induced damage threshold (T) of a sacrificial optical element within an electro-optical system without increased system reflectivity. A sacrificial optical element including input and output surfaces is located normal to the optical axis at an intermediate focal plane of the system and a micro-prism structure is also present on at least one of the surfaces.

Claims

1. An arrangement for reduced laser induced damage threshold (LIDT) of an electro-optical system without increased system reflectivity comprising:

a transmissive sacrificial optical element including input and output surfaces, located normal to the optical axis at an intermediate focal plane of an electro-optical system;

a micro-prism structure means on at least one of said input and output surfaces, whereby a reduced LIDT is achieved on the order of 5 times that of a flat polished surface, and reflectance of less than 0.01 is achieved.

2. The arrangement of claim 1 wherein the micro-prism structure means on at least one of said input and output surfaces further includes a crossed-grating structure.

3. A technique for reducing laser induced damage threshold (LIDT) of an electro-optical system without increased reflectivity comprising:

providing a transmissive sacrificial optical element including input and output surfaces;

providing a micro-prism structure on at least one of said input and output surfaces;

inserting the transmissive sacrificial optical element at an intermediate focal plane of the system, normal to the optical axis, whereby a reduced LIDT is achieved on the order of 5 times that of a flat polished surface, and reflectance of less than 0.01 is achieved.