Optical system and method

• US 6,842,549 B2
• Filed: 08/20/2002
• Issued: 01/11/2005
• Est. Priority Date: 08/20/2001
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: So, John Ling Wing
• Primary Examiner(s): Tarcza, Thomas H.
• Assistant Examiner(s): Hughes, Deandra M.
• Application Number:
  US10/224,146
• Publication Number:
  US 20030086139A1
• Time in Patent Office: 875 Days
• Field of Search: 385/15, 359/337.2, 359/563
• US Class Current: 385/15
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 5/203 having holographic or diffractive elements diffraction gratings per se G02B5/18; holographic elements per se G02B5/32; generating the spectrum using diffraction elements G01J3/18
• CPC Class Codes: G02B 6/2706 as bulk elements, i.e. free space arrangements external to a light guide, e.g. polarising beam splitters
• CPC Class Codes: G02B 6/278 Controlling polarisation mode dispersion [PMD], e.g. PMD compensation or emulation PMD minimised transmission systems H04B10/2569
• CPC Class Codes: G02B 6/2793 Controlling polarisation dependent loss, e.g. polarisation insensitivity, reducing the change in polarisation degree of the output light even if the input polarisation state fluctuates
• CPC Class Codes: G02B 6/2931 Diffractive element operating in reflection
• CPC Class Codes: G02B 6/29313 characterised by means for controlling the position or direction of light incident to or leaving the diffractive element, e.g. for varying the wavelength response switching G02B6/35
• CPC Class Codes: G02B 6/29389 Bandpass filtering, e.g. 1x1 device rejecting or passing certain wavelengths G02B6/2938 takes precedence
• CPC Class Codes: G02B 6/29391 Power equalisation of different channels, e.g. power flattening
• CPC Class Codes: G02B 6/29394 Compensating wavelength dispersion G02B6/29376 takes precedence; dispersion compensated optical transmission systems H04B10/2507
• CPC Class Codes: G02B 6/29395 configurable, e.g. tunable or reconfigurable switching G02B6/35
• CPC Class Codes: G02B 6/3512 the optical element being reflective, e.g. mirror
• CPC Class Codes: G02B 6/356 in an optical cross-connect device, e.g. routing and switching aspects of interconnecting different paths propagating different wavelengths to (re)configure the various input and output links switching polarized beams G02B6/3594; power equalizers G02B6/356 and G02B6/3594; path selecting means H04Q11/0001
• CPC Class Codes: G02B 6/3588 of the processed beams, i.e. controlling during switching of orientation, alignment, or beam propagation properties such as intensity, size or shape
• CPC Class Codes: H04B 10/2941 using an equalising unit, e.g. a filter H04B10/296 takes precedence

Abstract

Adaptive dynamic optical filters with wavelength spreading onto a micromirror array and re-configurable attenuation according to measured intensity as a function of wavelength.

Claims

1. A dynamic optical filter, comprising:

a) an input wavelength spreader;

b) an array of micromirrors positioned to reflect radiation from said wavelength spreader; and

c) an output wavelength combiner positioned to receive radiation reflected from said micromirrors;

d) wherein said micromirrors may be adjusted to vary the portion of radiation within a wavelength band reflected towards said output wavelength combiner and said spreader spreads a wavelength band to an oblong area on said micromirror array.

2. The filter of claim 1, wherein:

said spreader spreads adjacent wavelength bands to overlapping areas on said micromirror array.

3. An adaptive dynamic optical filter, comprising:

(a) an input wavelength spreader;

(b) an array of micromirrors positioned to reflect radiation from said wavelength spreader;

(c) an output wavelength combiner positioned to receive radiation reflected from said micromirrors; and

(d) feedback control with input coupled to said output combiner and said output coupled to said array of micromirrors;

(e) wherein said micromirrors may to adjusted to vary the portion of radiation within a wavelength band reflected towards said output wavelength combiner and said feedback control monitors the relative phase as a function of wavelength.

4. An adaptive dynamic optical filter, comprising:

(a) an input wavelength spreader;

(b) an array of micromirrors positioned to reflect radiation from said wavelength spreader;

(c) an output wavelength combiner positioned to receive radiation reflected from said micromirrors; and

(d) feedback control with input coupled to said output combiner and said output coupled to said array of micromirrors;

(e) wherein said micromirrors may to adjusted to vary the portion of radiation within a wavelength band reflected towards said output wavelength combiner and said feedback control monitors the relative group velocity as a function of wavelength.