公开(公告)号：CA2190915C

公开(公告)日：2003-08-12

申请号：CA2190915

申请日：1996-11-21

Applicant: LITTON SYSTEMS INC

Inventor： HALL DAVID B

IPC: G02B6/00 ,  G01J9/02 ,  H04B10/04 ,  H04B10/06 ,  H04B10/142 ,  H04B10/148 ,  H04B10/152 ,  H04B10/158

Abstract: A polarization diversity receiver system for yielding multiple heterodyne optical output signals from an incident optical beam having a p-polarized component and an s-polarized component comprises first and second sequentially-arrayed polarizing beamsplitters, and three photodetectors, eac h of which receives a heterodyne optical signal. The polarization diversity receiver system tracks the largest of these three signals, and uses only thi s largest one for subsequent signal processing. There is a minimum for this largest signal that is dependent on the input polarizations of the two optic al fields whose beat note is the heterodyne signal. Thus, the object is to maximize the minimum of this largest of the three heterodyne signals. The first polarizing beamsplitter ideally splits the incident beam into a transm itted beam portion including approximately 100% of the p-polarized component and approximately 33% of the s-polarized component, and a reflected beam portion including approximately 0% of the p-polarized component and approximately 67% of the s-polarized component. The reflected beam portion exits from the first polarizing beamsplitter as a first heterodyne optical o utput signal, and impinges on a first photodetector. The transmitted beam portion exits from the first beamsplitter, and then undergoes an effective 45O rotat ion of its polarization eigenstates around its axis of propagation, either prior to or during its passage through the second polarizing beamsplitter. The second beamsplitter splits the rotated transmitted beam portion into second and thi rd heterodyne optical output signals, which respectively impinge upon second an d third photodetectors.

公开(公告)号：CA2438727A1

公开(公告)日：2002-09-06

申请号：CA2438727

申请日：2001-10-11

Applicant: LITTON SYSTEMS INC

Inventor： HALL DAVID B ,  CHERBETTCHIAN AGOP H ,  FERSHT SAMUEL N ,  STEWART ROBERT E

IPC: B81B3/00 ,  B81C1/00 ,  G02B6/35 ,  G02B26/08 ,  B81B7/00 ,  B81B7/02 ,  G02B26/02

Abstract: A bi-stable micro-actuator is formed from a first and a second silicon-on- insulator wafer fused together at an electrical contact layer. A cover has a V- groove that defines an optical axis. A collimated optical signal source in t he V-groove couples an optical signal to an optical port in the V-groove. A mirror surface on the transfer member blocks or reflects the optical signal. The transfer member has a point of support at the first and second end. The central portion of the transfer member carrying a mirror is displaced from t he compressive axis with transfer member in a bowed first or second state. The mirror blocks or reflects the optical axis. An expandable structure applies a compressive force between the first and second point of support along the compressive axis to hold the transfer member in a bowed first state or a bow ed second state. A control signal is applied to a heating element in the expandable structure to reduce the compressive force transferring the transf er member to a second state. The central portion of the transfer member moves from a bowed first state past the compressive axis into a bowed second state to clear the optical axis.

公开(公告)号：NO20002415D0

公开(公告)日：2000-05-09

申请号：NO20002415

申请日：2000-05-09

Applicant: LITTON SYSTEMS INC

Inventor： HALL DAVID B

IPC: G01D5/244 ,  G01D5/353 ,  G02F

Abstract: Quadrature signals Q and in-phase signals I output from a pathlength mismatched interferometric sensor array (10) are normalized by sampling the signals to obtain a first set of values Qk = Q0Bk sin φk corresponding to the sine of the phase shift and a second set of values Ik = I0Bk cos φk corresponding to the cosine of the phase shift where k is a running index of the set of consecutive samples of Q and I. A quantity DQk =|Qu(k))2 -(Qs(k))2| is calculated for the quadrature signals; and a quantity DIk = |(Iu(k))2 -(Is(k))2| is calculated for the in-phase signals, where u(k) and s(k) are parameters used to determine indices that select specific sampled signals and k is a running index of the set of consecutive samples of Q and I. The normalization factor is then calculated as the ratio R = QNIN whereQN = k=N1N2 DQk andIN = k=N1N2DIk.

公开(公告)号：BR9800921A

公开(公告)日：1999-09-14

申请号：BR9800921

申请日：1998-03-17

Applicant: LITTON SYSTEMS INC

Inventor： HALL DAVID B

IPC: G01J3/26 ,  G01L9/00

Abstract: A pressure sensing system (10) employs a plurality of pulsed lasers (12a, 12b, 12c, 12d), each emitting a distinct wavelength ( lambda 1, lambda 2, lambda 3, lambda 4) whereby a multiplexed incident beam is generated. The incident beam is split into a first portion directed to a first photodetector (18) that generates a reference signal (R) for each wavelength, and a second portion that interrogates a Fabry-Perot pressure sensor (16). The interrogation beam portion is phase-modulated by gap width variations in the sensor, and is transmitted to a second photodetector (20) that generates a measured intensity signal (5) for each wavelength. For each wavelength, the ratio (S/R) of the measured intensity signal (S) to the reference intensity signal (R) is taken, and yields two terms, one of which is an interference term that is proportional to the cosine of the Fabry-Perot phase shift angle phi , which is a function of the gap width. By choosing wavelengths that are in quadrature relationship for a nominal. Fabry-Perot gap width, the algebraic differences can be taken among the ratios to yield two expressions proportional, respectively, to the cosine and sine of the phase shift angle phi . An arctangent calculation is used to obtain the measure of phi , which is proportional to the gap width, which, in turn, is a known function of the pressure applied to the sensor (16).

公开(公告)号：CA2240550A1

公开(公告)日：1999-01-31

申请号：CA2240550

申请日：1998-07-07

Applicant: LITTON SYSTEMS INC

Inventor： FREDERICK DONALD A ,  HALL DAVID B

IPC: H04B10/00 ,  G01L11/02 ,  G08C15/00

Abstract: A pressure measuring device which utilizes an array of optical, non-acoustic pressure sensors with a laser light source which generates a pulsed light signal into a light transmitting cable, wherein the pulsed light signal propagates along the light transmitting cable through the array of optical pressure sensors. A plurality of optical couplers are attached to the light transmitting cable at multiple locations spaced apart from one another in order to branch off at least a portion of the pulsed light each location. Each of the plurality of optical couplers includes a respective optical pressure sensor and a pressure insensitive reflector, wherein the branched off portion of the pulsed light signal is transmitted into to both the optical pressure sensor and the reflector. Each optical pressure sensor reflects a pressure indicating signal ba ck into the optical coupler, while the pressure insensitive reflector reflects a reference signal back into the optical coupler. The pressure indicating signal and the reference signal are reflected through the optical coupler into the ligh t transmitting cable as a pair of non-overlapping pulsed signals, which are then retrieved from the light transmitting cable by a signal detector. The retrieved pressure indicating signal is compared with the retrieved reference signal to determine the pressure acting upon the optical pressure sensor.

公开(公告)号：NO982586A

公开(公告)日：1998-12-07

申请号：NO982586

申请日：1998-06-05

Applicant: LITTON SYSTEMS INC

Inventor： HALL DAVID B ,  FERSHT SAMUEL N

IPC: G01P15/03 ,  G01B9/02 ,  G01B11/00 ,  G01H9/00 ,  G01L9/00 ,  G02F1/29 ,  G01J9/02

CPC classification number: G01L9/0077

公开(公告)号：NO981212A

公开(公告)日：1998-09-21

申请号：NO981212

申请日：1998-03-18

Applicant: LITTON SYSTEMS INC

Inventor： HALL DAVID B

IPC: G01J3/26 ,  G01L9/00 ,  G01H9/00

CPC classification number: G01L9/0079 ,  G01J3/26

公开(公告)号：NO983282D0

公开(公告)日：1998-07-16

申请号：NO983282

申请日：1998-07-16

Applicant: LITTON SYSTEMS INC

Inventor： FREDERICK DONALD A ,  HALL DAVID B

IPC: H04B10/00 ,  G01L11/02 ,  G08C15/00 ,  G01L

Abstract: A pressure measuring device which utilizes an array of optical, non-acoustic pressure sensors (22) with a laser light source (12) which generates a pulsed light signal into a light transmitting cable (16), wherein the pulsed light signal propagates along the light transmitting cable through the array of optical pressure sensors. A plurality of optical couplers (18) are attached to the light transmitting cable (16) at multiple locations spaced apart from one another in order to branch off at least a portion of the pulsed light each location. Each of the plurality of optical couplers includes a respective optical pressure sensor (22) and a pressure insensitive reflector (26), wherein the branched off portion of the pulsed light signal is transmitted into both the optical pressure sensor (22) and the reflector (26). Each optical pressure sensor (22) reflects a pressure indicating signal back into the optical coupler (18), while the pressure insensitive reflector (26) reflects a reference signal back into the optical coupler. The pressure indicating signal and the reference signal are reflected through the optical coupler (18) into the light transmitting cable as a pair of non-overlapping pulsed signals, which are then retrieved from the light transmitting cable by a signal detector (32) . The retrieved pressure indicating signal is compared with the retrieved reference signal to determine the pressure acting upon the optical pressure sensor.

公开(公告)号：NO965283A

公开(公告)日：1997-06-12

申请号：NO965283

申请日：1996-12-10

Applicant: LITTON SYSTEMS INC

Inventor： HALL DAVID B

IPC: G02B6/00 ,  G01J9/02 ,  H04B10/04 ,  H04B10/06 ,  H04B10/142 ,  H04B10/148 ,  H04B10/152 ,  H04B10/158 ,  G02B27/10 ,  G02B27/28

CPC classification number: H04B10/61 ,  G01J2009/0261 ,  H04B10/614 ,  H04B10/64

公开(公告)号：CA2690400A1

公开(公告)日：2009-01-29

申请号：CA2690400

申请日：2008-07-22

Applicant: LITTON SYSTEMS INC

Inventor： HALL DAVID B

IPC: G02F1/01

Abstract: A method for balancing the optical intensity of a first ON state and a second ON state of an electro-optic switch having an RF input port and a DC port, wherein the application of a positive RF voltage results in the first ON state of the electro-optic switch and the application of a negative RF voltage results in the second ON state of the electro-optic switch, wherein the absolute value of the negative RF voltage associated with the. second ON state is approximately equal to the positive RF voltage associated with the first ON 1 state, and balancing the optical intensity of the first ON state and the second ON state by adjusting a voltage applied to the DC port to obtain minimum optical transmission in the OFF state of the electro-optic switch.