Silicon nanoparticle microcrystal nonlinear optical devices

• US 6,456,423 B1
• Filed: 05/17/2000
• Issued: 09/24/2002
• Est. Priority Date: 10/22/1999
• Status: Expired due to Fees

• Current Assignee: Board of Trustees of The University of Illinois
• Original Assignee: Board of Trustees of The University of Illinois
• Inventors: Nayfeh, Munir H., Belomoin, Gennadiy, Barry, Nicholas, Akcakir, Osman
• Primary Examiner(s): Lee, John D.
• Application Number:
  US09/572,121
• Time in Patent Office: 860 Days
• Field of Search: 359/326-328, 324/96, 324/97
• US Class Current: 359/328
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: G02B 6/10 of the optical waveguide type G02B6/02, G02B6/24 take precedence; devices or arrangements for the control of light by electric, magnetic, electro-magnetic or acoustic means G02F1/00; transferring the modulation of modulated light G02F2/00; optical logic elements G02F3/00; optical analogue/digital converters G02F7/00
• CPC Class Codes: G02F 1/3509 Shape, e.g. shape of end face
• CPC Class Codes: G02F 1/3551 Crystals
• CPC Class Codes: G02F 1/37 for second-harmonic generation G02F1/3532 takes precedence
• CPC Class Codes: G02F 2202/104 poly-Si
• CPC Class Codes: G02F 2202/36 Micro- or nanomaterials
• CPC Class Codes: H01S 3/163 characterised by a crystal matrix
• CPC Class Codes: H01S 3/169 Nanoparticles, e.g. doped nanoparticles acting as a gain material
• CPC Class Codes: H01S 5/041 Optical pumping
• CPC Class Codes: H01S 5/10 Construction or shape of the optical resonator , e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region H01S5/20 takes precedence
• CPC Class Codes: H01S 5/30 Structure or shape of the active region; Materials used for the active region
• CPC Class Codes: H01S 5/3031 Si
• CPC Class Codes: H10N 30/85 Piezoelectric or electrostrictive active materials
• CPC Class Codes: H10N 30/852 Composite materials, e.g. having 1-3 or 2-2 type connectivity

Abstract

Harmonic incident radiation is obtained from a silicon nanoparticle microcrystal or microcrystal film. The preferred film comprises silicon nanoparticles, dimensioned on the order of one nanometer, reconstituted into a device quality crystalline film. The microcrystal film emits the second harmonic of incident radiation for excitations in the range of about 600-1000 nm. A preferred device according to the invention includes a silicon nanoparticle microcrystal film formed on a substrate, such as silicon or glass. Crystals of the silicon nanoparticles, due to the harmonic response, also demonstrate the capability to serve as piezoelectric material and as an improved biological marker. Since the emission response of the silicon nanoparticle crystals will be influenced by surrounding electric fields, the microcrystals also provide for electrochromatic mapping of electric field distribution in general and in electronic devices.

Claims

1. A nonlinear optical device for accepting excitation at a given frequency and emitting harmonics of the given frequency, the device comprising:

a silicon nanoparticle microcrystal, said microcrystal emitting a beam of the second harmonic of incident radiation beam when the incident radiation beam is in a range of incident radiation having a wavelength from about 600-1000 nm, and emitting another beam up shifted from a frequency of the second harmonic of incident radiation.

2. The device of claim 1, wherein said microcrystal is part of a microcrystal film formed on a substrate.

3. The device of claim 2, wherein said substrate comprises a silicon substrate.

4. The device of claim 2, wherein said substrate comprises a glass substrate.

5. The device of claim 2, wherein said substrate comprises a parafarin substrate.

6. A method for second harmonic imaging, the method comprising:

labeling biological cells with crystallized silicon nanoparticle microcystal material;

subjecting a host including labeled biological cells to incident radiation;

detecting the second harmonic of the incident radiation.

7. A method of monitoring electric fields, the method comprising steps of:

placing silicon nanoparticle microcrystal film in an area of interest;

subjecting the microcrystal film to incident radiation;

monitoring emissions from the microcrystal film to determine an electrical field strength in the area of interest.

8. The method according to claim 7, wherein the area of interest is a region of a semiconductor device.

9. The method according to claim 7, further comprising a step of monitoring conditions of the semiconductor device and correlating such conditions to the electric field.