The imaging lens includes, in order from an object side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having positive refractive power, and a fifth lens group having negative refractive power. In a case of changing focus from an object at infinity to an object at the closest distance, the first lens group is immovable, and the second lens group and the fourth lens group are moved in an optical axis direction along different trajectories from each other. In addition, predetermined conditional expressions (1) to (3) are satisfied.

Optomechanical device for frequency doubling enhancement are described. The devices include a substrate through which light of a first wavelength is introduced, a first reflector mirror, a conductive layer disposed on the first reflector mirror, and a second mirror spaced apart from the conductive layer, thereby forming an optical cavity between the second mirror and the conductive layer. The devices also include a power source coupled to the second mirror and the conductive layer and a monolayer of non-linear optical material disposed within the optical cavity, the monolayer being configured to produce light of a second wavelength upon interaction with the light of the first wavelength. The second mirror is deformable upon introduction of voltage from the power source and deformation of the second mirror changes a length of the optical cavity, thereby enhancing a power output of the light of the second wavelength produced by the monolayer.

The wavelength variable optical filter includes a first substrate, a second substrate, and a bonding film, the bonding film is in contact with a first reflective film and a second reflective film to thus join the first substrate with the second substrate, the bonding film has transparency with respect to light of a predetermined wavelength range, and an optical path extending through the first reflective film, the bonding film, and the second reflective film has transparency with respect to light of the predetermined wavelength range and has no peak of transmittance with respect to a wavelength range measured by the wavelength variable filter.

An electrowetting device is provided that includes a lower substrate and an upper substrate facing each other, a first electrode positioned on the lower substrate, an edge electrode positioned on the lower substrate and adjacent to an edge of the first electrode, a hydrophobic insulating layer positioned on the first electrode and the edge electrode, a partition positioned on the lower substrate, a second electrode positioned on the upper substrate, and a first liquid and a second liquid positioned between the upper substrate and the lower substrate, wherein an electric field of a portion where the edge electrode is positioned is smaller than an electric field of a portion where the first electrode is positioned.

A wavelength variable interference filter includes a fixed substrate, a movable substrate that faces the fixed substrate, a pair of reflective films, a fixed extraction electrode provided on the fixed substrate, and a movable connection electrode that is provided on the movable substrate and is in contact with the fixed extraction electrode at a connection position, in which the movable substrate includes a first groove that is provided at the connection position in a plan view in which the fixed substrate and the movable substrate are viewed from a substrate thickness direction, and a second groove that has a larger area than an area of the first groove in the plan view and is connected to the first groove.

The imaging lens includes, in order from an object side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having positive refractive power, and a fifth lens group having negative refractive power. In a case of changing focus from an object at infinity to an object at the closest distance, the first lens group is immovable, and the second lens group and the fourth lens group are moved in an optical axis direction along different trajectories from each other. In addition, predetermined conditional expressions (1) to (3) are satisfied.

The imaging lens consists of, in order from an object side, a positive first lens L1, a negative second lens L2, a positive third lens L3, and a positive fourth lens L4. Conditional expressions relating to a focal length f of an entire system, a combined focal length f234 of the second lens L2 to the fourth lens L4, an Abbe number d1 of the first lens L1, an Abbe number d2 of the second lens L2, a radius of curvature R1 of a surface of the first lens L1 on the object side, and a radius of curvature R2 of a surface of the first lens L1 on an image side: 0.4<f/f234<2; d1<50; 5<d1d2<26; 5<(R1+R2)/(R1R2)<0.9 are satisfied.

A filter for filtering a broadband beam and in one embodiment a fluorescence measurement system comprising such a filter. The system includes a broadband light source arranged to provide a broadband beam, a first tunable element arranged to filter at least a portion of the broadband beam thereby providing filtered light and a control unit arranged to provide a control signal to the first tunable element. In one embodiment the first tunable element is an acousto-optic filter (AOTF) and the control signal to the AOTF is an acoustic RF signal provided by a Voltage Controlled Oscillator (VCO) arranged so the AOTF provide a high out-of-band suppression.

An optical cell may include a first port coupled to a second port by an optical path. The optical cell may also include a compensator disposed in the optical path. The compensator may be rotatable about an axis. Rotating the compensator about the axis may vary a distance that the optical path passes through the compensator thereby changing the optical path length of the optical path.

A first component having a plate shape includes a first incident surface and a first emission surface disposed on the opposite side of the first incident surface. The first component is made of light transmissive material having an electrostrictive effect. The first component further includes a first transparent electrode formed on the first incident surface, and a second transparent electrode formed between the first emission surface and a first reflective film.