Signal beam

About: Signal beam is a research topic. Over the lifetime, 1881 publications have been published within this topic receiving 20717 citations.

Multichannel optical variable attenuator

Abstract: PROBLEM TO BE SOLVED: To provide a multichannel optical variable attenuator with a small device scale, a simple control circuit and a short control time. SOLUTION: This attenuator is provided with an optical attenuation part 10 containing optical waveguides 121-12N provided on a common substrate 11 and a control circuit 20 controlling attenuation amounts of respective signal beams propagating through respective optical waveguides 121-12N. The optical attenuation part 10 propagates the signal beam of a wavelength λi among plural signal beams λ1-λN demultiplexed at every channel of a different wavelength in a prescribed wavelength band to the optical waveguide 12i, and attenuates the signal beam λi (i=1, 2,..., N) with a variable attenuation amount at every channel. The control circuit 20 controls so that the attenuation amounts of respective signal beams in respective optical waveguides 121-12N are changed with a prescribed change rate at every channel for a control signal sent from a control signal sending part, and fixes nearly the intensity of respective signal beams attenuated by respective optical waveguides 121-12N.

Scanning type microscope and scanning type microscope system

Abstract: PROBLEM TO BE SOLVED: To acquire a low noise image in high speed in a scanning type microscope.SOLUTION: A scanning type microscope comprises a light source unit, first scanning means 114a, a first beam restriction body 115a and a light quantity detector 118. The light source unit emits irradiation beams to irradiate to a sample from first and second radiation points. The first scanning means 114a changes deflection direction of the irradiation beam. The first beam restriction body 115a has plural pores 115as to pass the irradiation beam. The light quantity detector 118 detects the reception quantity of a signal beam caused by the irradiation to the sample. The first scanning means 114a can move a scanning point along the first scanning direction by changing the deflection direction of the irradiation beam. The plural pores 115as are placed so that the irradiation beams emitted from the first and second radiation points pass through the pore 115as at different time depending on the continuous variation of the deflection direction by the first scanning means 114a.

Wave-front matching measurement in coherent CO 2 laser-radar

Abstract: Wave-front matching of the local oscillator beam and the signal beam is of vital importance in optical heterodyne efficiency. A method for aligning the local oscillator beam and the signal beam is described. Mixing efficiency is improved. One can directly observe the matching procedure on an oscilloscope.

Waveguide type optical device using large 3rd non-linear optical material and method for operating the same

Abstract: Disclosed is a waveguide type optical device utilizing a nonlinear refractive index change according to a large 3 rd order nonlinear optical phenomenon. The waveguide type optical device includes a signal beam waveguide through which a signal beam propagates; and a pump beam waveguide through which a pump beam propagates, wherein the pump beam waveguide is disposed adjacent to the signal beam waveguide so that the pump beam can be coupled to the signal beam waveguide, the signal beam waveguide is made of nonlinear optical materials with large 3 rd order nonlinear optical property and the pump beam waveguide is made of linear optical materials, and the wavelength range of the signal beam is different from that of the pump beam. By such a structure, the pump beam is coupled to one arm of the signal beam waveguide, thereby generating a 3 rd nonlinear phenomenon on one arm of the waveguide through which the signal beam passes. Therefore, the waveguide optical device which implements an all-optical communication device operating as an optical device and can be integrated is provided.

Apparatus for recording and reproducing hologram

Abstract: A hologram recording and reproducing apparatus including: a coherent light source; a beam splitter which splits a beam emitted from the coherent light source into a signal beam and a reference beam; a signal beam forming unit which modulates the signal beam split and directs the modulated signal beam onto a hologram recording medium; and a reference beam forming unit which directs the reference beam to be irradiated onto a location on the hologram recording medium which overlaps with a location on the hologram recording medium on which the signal beam is incident, wherein the signal beam forming unit includes: a first light guide member which transmits the signal beam split by the beam splitter; a spatial light modulator (SLM) which modulates the signal beam transmitted through the first light guide member; and a holographic Fourier transformation optical device which focuses the modulated signal beam onto the hologram recording medium.