A monolithic spectrometer for spectrally resolving light, the spectrometer comprising a body of solid material having optical surfaces configured to guide the light along an optical path (E1,E2,E3,E4) inside the body, the optical surfaces comprising - an entry surface configured to receive the light to enter into the body as an entry beam; - a collimating surface configured to receive the entry beam and to reflect the entry beam as a collimated beam; - a grating surface configured to receive the collimated beam and to reflect diffracted beams (La,Lb,Lc) in different directions according to a wavelength (λa,λb,λc) dependent diffraction angle (θa, θb, θc); - a first focusing section configured to receive at least part of a first diffracted beam (La) having a first wavelength (λa) the first focusing section having a first continuously functional optical shape (Ca) to focus all received parts of the first diffracted beam (La) onto a first focal position (fa) in an imaging plane outside the body; - a second focusing section configured to receive at least part of a second diffracted beam (Lb) having a second wavelength (λb), distinct from the first wavelength (λa), the second focusing section having a second continuously functional optical shape (Cb) to focus all received parts of the second diffracted beam (Lb) onto a second focal position (fb) in the imaging plane, the second focal position (fb) being distinct from the first focal position (fa); and - an exit surface arranged in the optical path between the focusing sections (6a,6b) and the imaging plane to have the light exit the body; wherein the optical path (E1,E2,E3,E4) defines a two dimensional plane of the body transverse to the optical surfaces (3,4,5,6,8), characterized in that: - the second continuously functional optical shape (Cb) is separated from the first continuously functional optical shape (Ca) by an optical discontinuity (Dab) there between, wherein the optical discontinuity (Dab) extends transverse to said plane of the body, and in that - light (La) focused onto the imaging plane by the first focusing section has an average angle of incidence (β1) that is smaller than an average angle of incidence (β2) of light (Lb) focused onto the imaging plane by the second focusing section, wherein the first focusing section spans a larger opening angle (α1) than an opening angle (α2) of the second focusing section. - an entry surface configured to receive the light to enter into the body as an entry beam; - a collimating surface configured to receive the entry beam and to reflect the entry beam as a collimated beam; - a grating surface configured to receive the collimated beam and to reflect diffracted beams (La,Lb,Lc) in different directions according to a wavelength (λa,λb,λc) dependent diffraction angle (θa, θb, θc); - a first focusing section configured to receive at least part of a first diffracted beam (La) having a first wavelength (λa) the first focusing section having a first continuously functional optical shape (Ca) to focus all received parts of the first diffracted beam (La) onto a first focal position (fa) in an imaging plane outside the body; - a second focusing section configured to receive at least part of a second diffracted beam (Lb) having a second wavelength (λb), distinct from the first wavelength (λa), the second focusing section having a second continuously functional optical shape (Cb) to focus all received parts of the second diffracted beam (Lb) onto a second focal position (fb) in the imaging plane, the second focal position (fb) being distinct from the first focal position (fa); and - an exit surface arranged in the optical path between the focusing sections (6a,6b) and the imaging plane to have the light exit the body; - the second continuously functional optical shape (Cb) is separated from the first continuously functional optical shape (Ca) by an optical discontinuity (Dab) there between, wherein the optical discontinuity (Dab) extends transverse to said plane of the body, and in that - light (La) focused onto the imaging plane by the first focusing section has an average angle of incidence (β1) that is smaller than an average angle of incidence (β2) of light (Lb) focused onto the imaging plane by the second focusing section, wherein the first focusing section spans a larger opening angle (α1) than an opening angle (α2) of the second focusing section.