Abstract: Fuel injection valves 3 each inserted into injection valve mounting holes 2 are fixed to cylinder head 1 through bifurcated clamps 21. Clamps 21 each include base portion 22 brought into abut contact with and supported on middle bolt 14a which is disposed at the middle portion of cam bracket 13, bifurcated tip end portion 23 pressing fuel injection valve 3, and intermediate portion 24 fastened by bolt 25 having a tip end portion which is screwed into cylinder head 1. Four clamps 21 are arranged on a straight line along a direction of a row of cylinders. Respective clamps 21 corresponding to cylinders #1 and #2 and respective clamps 21 corresponding to cylinders #3 and #4 are arranged symmetrically with each other such that base portions 22 are disposed on an outside. Core supporting hole 31 is disposed at a central portion of cylinder head 1 which is free from coverage by clamp 21. With this construction, it is possible to effectively release gas.

Abstract: A wavelength selection switch includes a diffraction grating that spectrally separates entering light, a focusing optical system that receives the light spectrally separated by the diffraction grating and focuses the light at a predetermined position, a deflection member that is arranged at the predetermined position and includes deflection elements that deflect the light entering through the focusing optical system, a base on which the diffraction grating, the focusing optical system, and the deflection member are mounted, and a deflection member position adjusting member that adjusts a position of the deflection member with respect to one of the diffraction grating and the focusing optical system. The deflection member position adjustment member includes a positioning member that determines a reference position of the deflection member in a direction of spectral separation of the diffraction grating, and a guide member that guides the deflection member in the direction of spectral separation.

Abstract: A wavelength selection switch includes a diffraction grating that spectrally separates entering light, a focusing optical system that receives the light spectrally separated by the diffraction grating and focuses the light at a predetermined position, a deflection member that is arranged at the predetermined position and includes deflection elements that deflect the light entering through the focusing optical system, a base on which the diffraction grating, the focusing optical system, and the deflection member are mounted, and a deflection member position adjusting member that adjusts a position of the deflection member with respect to one of the diffraction grating and the focusing optical system. The deflection member position adjustment member includes a positioning member that determines a reference position of the deflection member in a direction of spectral separation of the diffraction grating, and a guide member that guides the deflection member in the direction of spectral separation.