Hyo J Lee

6593582, Jul 15, 2003

May 11, 2001

09/852782

Hyo Sang Lee - Silver Spring MD
In Heon Hwang - Columbia MD
Coorg R. Prasad - Silver Spring MD

Science Engineering Services, Inc. - Burtonsville MD

G01N 2117

2504581, 2503411

A light detecting and ranging system and method for detecting airborne agents in which the system includes a laser which provides laser pulses of at least two wavelengths, a transmitter which transmits the laser pulses, a receiver which receives both elastically backscattered signals from airborne agents and fluorescence signals from the airborne agents, a common telescope which both focuses a laser beam transmission of the laser pulse from the transmitter to a far field and receives the elastically backscattered signals and the fluorescence signals from the far field, a digital detection system having at least one of a backscatter optical detector which detects the elastically backscattered signals and a fluorescence optical detector which detects the fluorescence signals from the airborne agents.

6683300, Jan 27, 2004

Sep 17, 2001

09/953403

Vladimir M. Doroshenko - Ellicott City MD
Victor V. Laiko - Ellicott City MD
Mikhail Yakshin - Ellicott City MD
Coorg R. Prasad - Silver Spring MD
Hyo Sang Lee - Silver Spring MD

Science Engineering Services, Inc. - Burtonsville MD

H01J 4916

250288, 250282, 250423 P

A method, system, and apparatus for mass spectroscopic analysis of an analyte solution in which a liquid volume of the analyte solution is irradiated with a light source resulting in desorption of solution-specific ions into a surrounding gas to produce gas-phase ions, the gas-phase ions are transferred to an inlet port of a mass analyzer, and the gas-phase ions are mass analyzed. More specifically, the apparatus may include a laser configured to pulse irradiate a surface of the analyte solution, a mass spectrometer configured to mass-analyze the gas-phase ions according to the mass-to-charge ratio, and a transfer mechanism configured to transfer the gas-phase ions to an inlet port of the mass spectrometer.

6683894, Jan 27, 2004

Apr 19, 2000

09/552579

Hyo Sang Lee - Silver Spring MD
Coorg R. Prasad - Silver Spring MD
Jun Zhang - Ellicott City MD

Science Engineering Services, Inc. - Burtonsville MD

H01S 310

372 20, 372 21, 372 22, 372 10, 372 30, 372101, 372105

A diode pumped solid state laser/OPO system widely tunable in mid infrared spectrum for infrared matrix assisted laser desorption/ionization (MALDI) mass spectroscopy is disclosed. Up to a few tens of milli-Joule, short pulse, tunable near infrared laser pulse is generated from an all solid state laser at a high pulse repetition rate up to one kHz. The tunable near-infrared laser pumps a Quasi-Phase Matching (QPM) OPO system to further shift the wavelength to the mid-IR range and to broaden the tuning range to as much as 3 m to effectively generate a widely tunable spectral output. The wide range tuning of the infrared output is accomplished by a narrow range tuning of the pump laser. The pump laser output is generated by a diode pumped tunable solid state laser module using either a Yb:YAG crystal or any other efficient tunable laser crystals. The wavelength range (2-5 m) covered by the solid state laser system is optimum for MALDI applications. This wavelength range is especially beneficial for large mass DNA analysis.

6876790, Apr 5, 2005

May 17, 2002

10/146920

Hyo Sang Lee - Silver Spring MD, US

Science & Engineering Services, Inc. - Burtonvsville MD

G02B006/32

385 33, 385 74, 385 79, 385 93

A method and apparatus for coupling a laser signal to an optical carrier. The method and associated apparatus control a power of the laser signal to a power density level below a damage threshold of the optical carrier, couple the laser signal to the optical carrier, and measure an output power of the laser signal at an exit of the optical carrier. By translating a focusing lens or an entrance of the optical carrier along an optical axis between the focusing lens and the entrance to the optical carrier, a range in measured power output is determined in which the laser signal is incident within the entrance of the optical carrier. The method and associated apparatus set a distance between the focusing lens and the entrance to the optical carrier such that the entrance to the optical carrier is at a position beyond a focal point of the focusing lens where the laser signal is divergent-coupled to the optical carrier.

7741618, Jun 22, 2010

Nov 18, 2005

11/281621

Hyo Sang Lee - Silver Spring MD, US
In Heon Hwang - Columbia MD, US
Coorg R. Prasad - Silver Spring MD, US

Science & Engineering Services, Inc. - Columbia MD

G01J 1/58

2504581

A system for detecting airborne agents. The system can include a laser source that provides laser pulses of at least two wavelengths, a transmitter that transmits the laser pulses, and a coupling mechanism configured to remotely couple the laser pulses between the laser source and the transmitter. The system can include a receiver receives both elastically backscattered signals from airborne agents and fluorescence signals from the airborne agents. The system can include a telescope both transmits a collimated laser beam of the laser pulse from the transmitter to a far field and receives the elastically backscattered signals and the fluorescence signals from the far field. The system can include a detection system having at least one of a backscatter optical detector that detects the elastically backscattered signals and one or more fluorescence optical detectors that detect the fluorescence signals in selected spectral band(s) from the airborne agents.

7884937, Feb 8, 2011

Apr 19, 2007

11/737547

Coorg Rangaswamy Prasad - Silver Spring MD, US
Bo Lin - Fairfax VA, US
Hyo Sang Lee - Silver Spring MD, US

Science & Engineering Services, Inc. - Columbia MD

G01N 21/00
G01J 5/00
G01J 5/02

356437, 2503381, 2503385, 25033911, 25033912, 25033913, 2503418

A method and apparatus for measuring target gas concentrations in an atmosphere. The method and apparatus emit in the atmosphere a laser beam tuned to a molecular absorption line of a target gas, receive a reflected signal affected by gas absorption of the target gas in the atmosphere, divide and direct the received signal into a first optical path and a second optical path including in one of the paths a correlation gas cell filled with a predetermined concentration of the target gas, detect transmitted signals through the first optical path and the second optical path, and calculate a target gas concentration by comparing a first signal transmitted through the first optical path to a second signal transmitted through the second optical path. The apparatus includes a laser source tunable to a specific molecular absorption line of a target gas and configured to emit in the atmosphere a laser beam having a spectral bandwidth greater than a full width of the molecular absorption line of the target gas, a receiver configured to receive a reflected signal affected by gas absorption of the target gas in the atmosphere, and at least one detector configured to detect transmitted signals through the first optical path and the second optical path.

7965391, Jun 21, 2011

Dec 22, 2009

12/644881

Coorg Rangaswamy Prasad - Silver Spring MD, US
Bo Lin - Fairfax VA, US
Hyo Sang Lee - Silver Spring MD, US

Science & Engineering Services, Inc. - Columbia MD

G01N 21/00
G01J 5/00
G01J 5/02

356437, 2503381, 2503385, 25033911, 25033912, 25033913, 2503418

A method and apparatus for measuring target gas concentrations in an atmosphere. The method and apparatus emit in the atmosphere a laser beam tuned to a molecular absorption line of a target gas, receive a reflected signal affected by gas absorption of the target gas in the atmosphere, divide and direct the received signal into a first optical path and a second optical path including in one of the paths a correlation gas cell filled with a predetermined concentration of the target gas, detect transmitted signals through the first optical path and the second optical path, and calculate a target gas concentration by comparing a first signal transmitted through the first optical path to a second signal transmitted through the second optical path. The apparatus includes a laser source tunable to a specific molecular absorption line of a target gas and configured to emit in the atmosphere a laser beam having a spectral bandwidth greater than a full width of the molecular absorption line of the target gas, a receiver configured to receive a reflected signal affected by gas absorption of the target gas in the atmosphere, and at least one detector configured to detect transmitted signals through the first optical path and the second optical path.

8024135, Sep 20, 2011

Apr 13, 2005

11/104505

Hyo Sang Lee - Silver Spring MD, US
Coorg R. Prasad - Silver Spring MD, US

Science & Engineering Services, Inc. - Columbia MD

G01N 21/64

702 40, 356 401

A system and method for detecting airborne agents. The system includes a semiconductor ultraviolet optical source configured to emit an ultraviolet light, a controller configured to generate a pseudo-random code for emission of the ultraviolet light modulated at the pseudo-random code, a telescope configured to focus the ultraviolet light to a distance from the source and to receive elastically backscattered signals and fluorescence signals from the distance, and a sensor configured to detect the elastically backscattered and fluorescence signals. The method generates a pseudo-random code and emits at least one wavelength of ultraviolet light modulated at the pseudo-random code, transmits the modulated ultraviolet light pulses to a distance from the source, receives elastically backscattered signals and fluorescence signals from the distance, and detects the elastically backscattered and fluorescence signals.