The invention provides light-emitting compositions, including lasing and fluorescent compositions. The invention particularly relates to programmable biological substrates, which fluoresce and/or lase, and which have a wide variety of different applications. The invention extends to use of the fluorescent compositions and lasing compositions comprising programmable biological substrates in fabricating lasers, and in various biological imaging applications, such as in assays.

The disclosed method and handheld analyzer of elemental concentration measurement is based on spectral analysis of high temperature highly ionized plasma generated by laser-generated pulses. Due to a high pulse energy and short pulse duration, high intensity singly and multiply charged ion lines in addition to neutral atomic lines are excited. The pulsed laser source of the disclosed analyzer is configured to output a train of pulses of signal light at a 1.5-1.6 signal wavelength at a pulse repetition rate from 0.1 to 50 kHz, pulses duration from 0.01 to 1.5 ns, pulse energy between 100 and 1000 uJ and has a beam spot on the surface of the sample varying 1 to 60 m. The above-described parameters provide at least a 20 GW/cm.sup.2 laser power density sufficient to induce a high temperature, highly ionized plasma (plasma) which allows measuring the carbon concentration in carbon steels by employing doubly charged ionic line CII with a detection limit down to 0.01% and other elements commonly present in carbon steels with detection limit below 0.01%.

Apparatus and methods for producing ultrashort optical pulses are described. A high-power, solid-state, passively mode-locked laser can be manufactured in a compact module that can be incorporated into a portable instrument. The mode-locked laser can produce sub-50-ps optical pulses at a repetition rates between 200 MHz and 50 MHz, rates suitable for massively parallel data-acquisition. The optical pulses can be used to generate a reference clock signal for synchronizing data-acquisition and signal-processing electronics of the portable instrument.

Apparatus and methods for producing ultrashort optical pulses are described. A high-power, solid-state, passively mode-locked laser can be manufactured in a compact module that can be incorporated into a portable instrument for biological or chemical analyses. The pulsed laser may produce sub-100-ps optical pulses at a repetition rate commensurate with electronic data-acquisition rates. The optical pulses may excite samples in reaction chambers of the instrument, and be used to generate a reference clock for operating signal-acquisition and signal-processing electronics of the instrument.

A method for in situ synthesis of graphene along a lengthwise direction of a waveguide applied to a photonic device includes processing an evanescent field of laser propagating in the waveguide to spread outward the waveguide, depositing a nickel thin film on a surface of the waveguide, growing graphene between a surface of the waveguide and a nickel thin film by irradiating telecommunication laser to a core of the waveguide, and removing the nickel thin film from the waveguide. Accordingly, graphene with high optical nonlinearity is in situ synthesized in the photonic device.

A solid-state laser amplifier includes a core material providing an active gain medium. A cladding material is on the core material that is the same material as the core material that further comprises a broadband absorber material. The cladding material suppresses transverse oscillations in solid-state, single-crystal or ceramic laser amplifiers by employing a native-material, solid-state, index-matched cladding containing an appropriate broadband absorber.

A passive mode-locked laser method and system, the system comprising a nonlinear optical loop comprising a resonant nonlinear element, coupled to an amplification section by a beam splitter, the beam splitter splitting a light beam from the amplification section into light beams propagating in opposite directions around the nonlinear optical loop, the resonant nonlinear element acting as both a nonlinear element and a narrow bandwidth filter for the laser system, allowing mode-locking operation of the system on a single resonance of the resonant nonlinear element.

A diode pumped solid state laser is provided which includes a ruby crystal optical gain medium and a high bandgap semiconductor laser diode (LD) or light emitting diode (LED) pump source to directly optically pump the gain medium. The high-bandgap semiconductor LD or LED is a semiconductor device whose chemical composition is chosen to provide output radiation at an approximate wavelength of 405 nm. The ruby crystal produces laser output at the relatively short wavelength of 694 nm.

In an embodiment, an integrated optical chip comprises: a substrate; a plurality of planar lightwave circuit-based optical components that are formed on one surface of the substrate; and a plurality of optical waveguides that are formed on the one surface of the substrate and that connect the plurality of optical components to one another. In the embodiment, the plurality of optical components includes a saturable absorber having nonlinear loss characteristics. The saturable absorber may comprise: a core layer that is formed on the one surface of the substrate; an overcladding layer that wraps around at least a part of the core layer; and a saturable absorption layer that is formed on at least a part of the overcladding layer and that is arranged so as to interact with an evanescent field of light guided through at least a part of the core layer.

A surface-emitting semiconductor laser system contains at least one MQW unit of at least three constituent QWs, axially separated from one another substantially non-equidistantly. The MQW unit is located within the axial extent covered, in operation of the laser, by a half-cycle of the standing wave of the field at a wavelength within the gain spectrum of the gain medium; immediately neighboring nodes of the standing wave are on opposite sides of the MQW unit. So-configured MQW unit can be repeated multiple times and/or complemented with individual QWs disposed outside of the half-cycle of the standing wave with which such MQW unit is associated. The semiconductor laser further includes a pump source configured to input energy in the semiconductor gain medium and a mode-locking element to initiate mode-locking.